Measurement of ambient air particulate pollutant concentrations and dry depositions for PS-1 combined with dry deposition plate at a wetland site     

Guor-Cheng Fang  Chao-Yang Huang  Kai-Hsiang Tsai  Kuang-Pu Ou Yang  You-Fu Xiao  Wen-Chuan Huang  Yuan-Jie Zhuang 《Environmental Earth Sciences》2018,77(3):109

In this study, the concentrations of ambient total suspended particulates (TSP) and their dry deposition were measured using a PS-1 sampler with dry deposition plates at a wetland sampling site in central Taiwan during a sampling period from October 2016 to December 2016. The PS-1 sampler was fixed at set distances (1.5 and 2 m) from a dry deposition plate, and sampled particulate pollutants were sampled to determine their concentrations and dry deposition rates simultaneously. A dry deposition plate 3 m from the PS-1 sampler was also used to collect dry deposition particulate. This plate was also used to compare dry depositions from ambient air, collected from new device. The results thus obtained indicated that the average dry deposition rates on the dry deposition plates that were 1.5 and 2 m from the sampler were 103.15 and 103.94 µg/m² min, respectively, in October, 83.36 and 100.18 µg/m² min in November, and 171.2 and 157.5 µg/m² min in December. These dry deposition rates were compared with that 3 m away from the PS-1 sampler. The statistical t test revealed no significant differences between the dry depositions on dry deposition plates at 1.5 and 2 m from the sampler. The dry deposition rates at 1.5 and 2 m from the sampler did not differ significantly from that at 3 m from the PS-1 sampler. This study proves that a PS-1 sampler can be combined with a dry deposition plate to measure TSP concentrations and dry depositions simultaneously using a single device.  相似文献   

Deformation effects of porosity variation on soil consolidation caused by groundwater table decline   总被引：1，自引：0，他引：1  

Tung-Lin Tsai  Weng-Shin Jang 《Environmental Earth Sciences》2014,72(3):829-838

Soil consolidation has been widely analyzed using the poroelastic theory. As soil consolidation proceeds, porosity variation leads to the changes in hydraulic conductivity, Young’s modulus, and body force. However, the combined deformation effect of porosity variation on soil consolidation is rarely examined. In this study, a poroelastic consolidation model used to simultaneously consider the changes in hydraulic conductivity, Young’s modulus, and body force was developed to investigate the combined deformation effect of porosity variation on soil consolidation caused by groundwater table decline. The results indicate that the deformation effect of porosity variation on soil consolidation is negligible when the body force number is <0.01. For body force numbers >0.01, soil displacement could be overestimated or underestimated if the combined deformation effect of porosity variation is not completely considered. The misestimation of soil displacement increases as the body force number increases. In addition, the combined deformation effect of porosity variation also affects the transmission of pore water pressure. Therefore, it could be concluded that a reliable analysis of soil consolidation must simultaneously account for the variations in hydraulic conductivity, Young’s modulus, and body force.  相似文献   

Tomographic imaging of the ionosphere using the GPS/MET and NNSS data     

L. -C. Tsai  C. H. Liu  W. H. Tsai  C. T. Liu 《Journal of Atmospheric and Solar》2002,64(18)

The earlier experiments of ionospheric tomography were conducted by receiving satellite signals from ground-based stations and then reconstructing electron density distribution from measures of the total electron content (TEC). In June 1994, National Central University built up the low-latitude ionospheric tomography network (LITN) including six ground stations spanning a range of 16.7° (from 14.6°N to 31.3°N) in latitude within 1° of 121°E longitude to receive the naval navigation satellite system (NNSS) signals (150 and 400 MHz). In the study of tomographic imaging of the ionosphere, TEC data from a network of ground-based stations can provide detailed information on the horizontal structure, but are of restricted utility in sensing vertical structure. However, an occultation observation mission termed the global positioning system/meteorology (GPS/MET) program used a low Earth orbiting (LEO) satellite (the MicroLab-1) to receive multi-channel GPS carrier phase signals (1.5 and 1.2 GHz) and demonstrate active limb sounding of the Earth's atmosphere and ionosphere. In this paper, we have implemented the multiplicative algebraic reconstruction technique (MART) to reconstruct and compare two-dimensional ionospheric structures from measured TECs through the receptions of the GPS signals, the NNSS signals, and/or both of the systems. We have also concluded the profiles retrieved from tomographic reconstruction showing much reasonable electron density results than the original vertical profiles retrieved by the Abel transformation and being in more agreement in peak electron density to nearby ionosonde measurements.  相似文献   

Delaunay triangulations in TIN creation: an overview and a linear-time algorithm     

Victor J. D. Tsai 《International journal of geographical information science》2013,27(6):501-524

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Polygon‐based texture mapping for cyber city 3D building models     

F. Tsai  H.‐C. Lin 《International journal of geographical information science》2013,27(9):965-981

The three‐dimensional building model is one of the most important components in a cyber city implementation. Currently, however, most building models do not have sufficient and accurate texture information. The lack of texture not only makes 3D building models less realistic in visualization, it may also fail to provide needed information in intricate applications. This study developed a polygon‐based texture mapping system to produce near photo‐realistic texture mappings for 3D building models. Textures of building exteriors were generated from mosaics of close‐range photographs acquired with commodity digital cameras. The developed system integrated multiple digital photographs to create texture mosaics that were continuous in geometric outlines and smooth in colour shadings, and correctly mapped them onto corresponding building model façades. A test example demonstrated that the resultant building model had more complete and accurate texture features as well as a near‐photo‐realistic appearance.  相似文献   

A probabilistic approach for earthquake risk assessment based on an engineering insurance portfolio     

Wen-Ko Hsu  Wei-Ling Chiang  Qiang Xue  Dung-Mou Hung  Pei-Chun Huang  Cheng-Wu Chen  Chung-Hung Tsai 《Natural Hazards》2013,65(3):1559-1571

This paper presents the construction classification of the existing engineering covers in Taiwan. The exposure profile and variable vulnerability during different construction phases are established for some kinds of classes of construction. Finally, we present a method and framework to estimate the probable maximum loss of engineering insurance portfolio during an earthquake with consideration of the dynamic nature of structural changes and exposure values during a construction project.  相似文献   

A research on the three-year performance of the regional emergency operation centers in Taiwan     

Chia-Chou Tsai  Jet-Chau Wen  Cheng-Mau Wu  Mei-Hsuan Chen 《Natural Hazards》2013,68(2):1109-1127

For a smooth lateral integration between Taiwan’s regional emergency operation centers (EOCs) and with local health, fire, and medical units, the operating performance of the emergency medical care law (EMCL) needs to be enhanced throughout the emergency medical service system. In this article, a 3-year comprehensive evaluation was adopted to analyze the performance evaluation of six regional EOCs and to initiate a proposed framework with an appropriate coordinated operation and notification mode for the regional EOCs with above three units. The study discovered that establishing a closer coordinated operation and notification model relationship for the EOCs with above three units was a key factor to provide real-time information delivery and query services. A common disaster information and medical resource exchange platform should be established in the future, and the EMCL that allows EOCs to be the official dedicated units should be amended. In addition, EOCs must be given a regulatory power and responsibility to execute their services, which allows them to play an active role rather than a passive role. This would effectively help to integrate the fire, health, and medical units uniformly in the rescue response operation of disaster incidents.  相似文献   

Recovery of Gallium and Arsenic from Gallium Arsenide Waste in the Electronics Industry     

Wei‐Ting Chen  Lung‐Chang Tsai  Fang‐Chang Tsai  Chi‐Min Shu 《洁净——土壤、空气、水》2012,40(5):531-537

Gallium arsenide (GaAs) has both high saturated electron velocity and high electron mobility, making it useful as a semiconductor material in a variety of applications, including light‐emitting diodes (LEDs), integrated circuits (ICs), and microwave appliances. A side effect of the use of gallium (Ga) is the production of a relatively large amount of hazardous waste. This study aimed at the recovery of Ga and arsenic (As) from GaAs waste using hydrometallurgical methods involving leaching and coagulation and a dry annealing process that involves annealing, vacuum separation, and sublimation by heating. Our research has shown that GaAs can be leached using nitric acid (HNO₃) to obtain 100% Ga and As with a leaching solution at pH 0.1, with subsequent adjustment of the leaching solution to pH 3 with sodium hydroxide (NaOH). Another method used a leaching solution at pH 2, then adjusting to pH 11 using NaOH. Ferric hydroxide (FeO(OH)) was added at 90°C after NaOH was added to the leaching solution. At pH 2 and 11, 55.5 and 21.9% of the As could be removed from the hazardous waste, respectively. The Ga could also be precipitated. When GaAs powder was heated to 1000°C over 3 h, 100% As removal was achieved, and 92.6% of the Ga was removed by formation of 99.9% gallium trioxide (Ga₂O₃). Arsenic was vaporized when the temperature was elevated to 1000°C, allowing arsenic trioxide (As₂O₃) to condense with 99.2% purity. The Ga₂O₃ powder produced was then dissolved and electrolyzed, allowing for 95.9% recovery of Ga with a purity of 99.9%.  相似文献   

Roles of soil-structure interaction and damping in base-isolated structures built on numerous soil layers overlying a half-space     

C. S. Tsai  C. I. Hsueh  H. C. Su 《地震工程与工程振动(英文版)》2016,15(2):387-400

This study examines the roles of soil-structure interaction (SSI), higher modes, and damping in a base-isolated structure built on multiple layers of soil overlying a half space. Closed-form solutions for the entire system, including a superstructure, seismic isolator, and numerous soil layers overlying a half-space, were obtained. The formulations obtained in this study simply in terms of well-known frequencies and mechanical impedance ratios can explicitly interpret the dynamic behavior of a base-isolated structure interacting with multiple soil layers overlying a half-space. The key factors influencing the performance of the isolation system are the damping ratio of the isolator and the ratio of the natural frequency of the fixed-base structure to that of the isolated structure by assuming that the superstructure moves as a rigid body. This study reveals that higher damping in the base isolator is unfavorable to higher mode responses that usually dominate the responses of the superstructure and that the damping mechanism plays an important role in transmitting energy in addition to absorbing energy. It is also concluded that it is possible to design a soft soil layer as an isolation system for isolating vibration energy.  相似文献   

Cyclic performance of large‐scale corroded reinforced concrete beams     

Yu‐Chen Ou  Li‐Lan Tsai  Hou‐Heng Chen 《地震工程与结构动力学》2012,41(4):593-604

Nine large‐scale beam specimens were constructed. Of which, one was used as the control, whereas the other eight ones were divided into four sets. Each set had two specimens and was subjected to accelerated corrosion using an imposed current for the same time interval. Following the corrosion, a specimen in each set was tested using cyclic loading to examine the seismic performance, whereas the other one was demolished to examine the extent of corrosion. Cyclic loading results indicated that with an increasing corrosion level, the ultimate drift, ductility, plastic rotation capacity, and energy dissipation of the beams initially increased and later decreased. The failure mode switched from flexural failure, largely owing to buckling of the longitudinal reinforcement to flexural‐shear failure, which is mainly caused by fracturing of the transverse reinforcement. Corrosion increased shear deformation and the spread of plasticity of the plastic hinge region. The residual flexural strength, as estimated by an empirical equation based on the maximum pit depth in the longitudinal reinforcement, closely corresponds to experimental values. Furthermore, the residual shear strength estimated based on the minimum reduced cross‐sectional area of transverse reinforcement correlates better with the experimental observations than that based on the weight loss. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献