Composite hydrogeological investigation and characterisation methods applied at a nuclear power plant site in Taiwan

Drawing from the lessons learnt from the Fukushima nuclear disaster in Japan, the assessment of subsurface environmental hazard around nuclear power plants has emerged as a critical task. Consequently, aiming to better understand the possible environmental impact of radiation leaks into the groundwater, a prescreening programme was initiated in 2011 by the Taiwanese government. As part of this programme, this study conducted various borehole prospecting techniques to identify in situ hydrogeological characteristics at Chin‐Shan Nuclear Power Plant. Borehole electrical log, sonic log and temperature/conductivity log were conducted to explain the regional lithologic conditions and permeability of the formation. In conjunction with this, the interwell tracer and pumping test was carried out to simultaneously determine the hydraulic parameters. In our opinion, the implementation of such in situ end‐to‐end investigations is essential in interpreting in situ fluid and solute transport dynamics prior to programming any numerical scheme for early warning, vulnerability assessment and regular monitoring of a nuclear power plant site.     

Modified toughness used to evaluate the effect of polymer modified asphalt on SMA

Abstract

Toughness, as defined in ASTM D5801, is the work used to stretch a specimen until fracture, and is used to evaluate the ability of polymer modified asphalt (PMA) to resist deformation. Fracture elongations in PMA are usually longer than 10 cm. However, it is almost impossible for asphalt concrete, with or without PMA, to endure such large deformation before fracture. It is presumed that an effective elongation exists for more effective determination of toughness. Principle component analysis (PCA) and single regression analysis were used in this study to evaluate the correlation between physical tests of PMA, including toughness and performance tests of Stonic Mastic Asphalt (SMA). Meanwhile, performance tests, including resilient modulus tests, creep tests and indirect tensile tests, were conducted on SMA samples. According to the results form Principle Components Analysis (PCA), it was observed that only a common factor affects the performance tests. Regression analyses were used to find common factors from physical tests of PMA. Correlation coefficients between toughness and performance tests were found to be better than other physical tests. When toughness was calculated with effective elongation (6.5 cm), R ² was 0.90. In our opinion, the desirable PMA should provide SMA enough work to resist the deformation while the deformation is still small. This result was also confirmed by observation of SEM and Rheological analysis. Modified toughness (calculated with effective elongation) considered as the common factor, is a simple method to evaluate the microstructure of PMA. Overall, modified toughness seems promising for use in evaluation of the effect of PMA on SMA.     

Quartz resonator assembling with TSV interposer using polymer sealing or metal bonding

This paper presents one wafer level packaging approach of quartz resonator based on through-silicon via (TSV) interposer with metal or polymer bonding sealing of frequency components. The proposed silicon-based package of quartz resonator adopts several three-dimensional (3D) core technologies, such as Cu TSVs, sealing bonding, and wafer thinning. It is different from conventional quartz resonator using ceramic-based package. With evaluation of mechanical structure design and package performances, this quartz resonator with advanced silicon-based package shows great manufacturability and excellent performance to replace traditional metal lid with ceramic-based interposer fabrication approach.     

Volume Shrinkage Induced by Interfacial Reaction in Micro-Ni/Sn/Ni Joints

Experiments are carried out to measure the volume shrinkage during solid-state reaction in micro-joints for three-dimensional integrated circuit applications. Surface profilometer is employed to measure the volume shrinkage for the reaction between Ni and Sn. The shrinkage is correlated with the microstructural evolution during the reaction. It is found that the volume shrinkage is released through both joint height reduction and void formation. The resulting internal stress and the void formation might post potential reliability issues.     

One‐Step Fast Synthesis of Li4Ti5O12 Particles Using an Atmospheric Pressure Plasma Jet

A one‐step process to fabricate crystalline Li₄Ti₅O₁₂(LTO) particles directly from solution using an atmospheric pressure plasma jet (APPJ) is reported. This process uses Ti and Li ions‐containing salt solutions as the precursor, which is ultrasonically nebulized and then transported to the downstream of the APPJ using a carrier gas. With an extremely short contact time (<0.1 s) between the precursor droplets and the plasma jet, crystalline LTO can be fabricated in one step without additional rinse and postannealing steps. The LTO particle size can be effectively controlled using a preheater, the precursor solution composition and concentration, and the carrier gas flow rate. By properly adjusting the operating condition, particles of diameters from 100 nm to few μm with various morphologies can be obtained. When used as an electrode material, the resulting LTO powders fabricated under selected conditions show specific capacities over 100 mAh/g even at 50 C rate.     

Development and Testing of an Energy Storage Material/Phase Change Material Enhanced Heat Sink

A concept of using energy storage material (ESM) or phase change material (PCM) to enhance the heat transfer dissipation by a conventional compact fin-based heat sink is demonstrated. An actual design is developed, fabricated, and tested to demonstrate the heat transfer enhancement. The heat sink is light weight (made with Aluminum) and miniature in size with a total fin length of 26 mm. Test results demonstrated that under a high peak load (4.4 W/cm²) and low duty power cycle (30/55 on/off ratio with a period of 85 sec), the peak temperature at the heating surface with the ESM/PCM heat sink is 5°C lower than that of a conventional heat sink. At the tip of the fin, the peak temperature with the ESM/PCM heat sink is 3°C lower than that of a conventional heat sink. When the external heat transfer coefficient increases (with increase air velocity), the impact of the PCM/ESM on the heat transfer performance is less. A numerical model, based on COMSOL, is developed to provide a theoretical understanding of the experimental observation.     

An intelligent skin‐color capture method based on fuzzy C‐means with applications

Consumer behavior is complicated. In the cosmetic market, personal intuition and fashion trends for color selection are guidelines for consumers. A systematic method for female facial skin‐color classification and an application in the makeup market are proposed in this study. In this article, face recognition with a large number of images is first discussed. Then, an innovative method to capture color at selected points is presented and complexion‐aggregated analysis is performed. This innovative method is an extension of face‐recognition theory. Images in RGB format are converted to CIELAB format during data collection and then Fuzzy C‐means theory is used to cluster and group the data. The results are classified and grouped in Lab value and RGB index. Two programs are created. The first program, “FaceRGB,” captures color automatically from images. The second program, “ColorFCM,” clusters and groups the skin‐color information. The results can be used to assist an expert system in the selection of customized colors during makeup and new‐product development.     

Buoyancy effects on the laminar boundary layer heat transfer along vertically moving cylinders

Abstract

The effects of buoyancy forces on the laminar boundary layer flow and heat transfer along vertically moving cylinders are analyzed for the cases of prescribed surface temperature and prescribed wall heat flux in power of streamwise distance. Local similarity solutions are obtained to show the effects of buoyancy parameters and the transverse curvature of the cylinder on the surface friction and heat transfer rate.