Wen C.-Y.,National Cheng Kung University |
Liang K.-P.,National Cheng Kung University |
Chen H.,University of Kang Ning |
Fu L.-M.,National Pingtung University of Science and Technology
Electrophoresis | Year: 2011
This paper presents a detailed numerical investigation of the novel active microfluidic mixer proposed by Wen et al. (Electrophoresis 2009, 30, 4179-4186). This mixer uses an electromagnet driven by DC or AC power to induce transient interactive flows between a water-based ferrofluid and DI water. Experimental results clearly demonstrate the mixing mechanism. In the presence of the electromagnet's magnetic field, the magnetic nanoparticles create a body force vector that acts on the mixed fluid. Numerical simulations show that this magnetic body force causes the ferrofluid to expand significantly and uniformly toward miscible water. The magnetic force also produces many extremely fine finger structures along the direction of local magnetic field lines at the interface in both upstream and downstream regions of the microchannel when the external steady magnetic strength (DC power actuation) exceeds 30Oe (critical magnetic Peclet number Pe m,cr = 2870). This study is the first to analyze these pronounced finger patterns numerically, and the results are in good agreement with the experimental visualization of Wen et al. (Electrophoresis 2009, 30, 4179-4186).The large interfacial area that accompanies these fine finger structures and the dominant diffusion effects occurring around the circumferential regions of fingers significantly enhance the mixing performance. The mixing ratio can be as high as 95% within 2.0s. at a distance of 3.0mm from the mixing channel inlet when the applied peak magnetic field supplied by the DC power source exceeds 60Oe. This study also presents a sample implementation of AC power actuation in a numerical simulation, an experimental benchmark, and a simulation of DC power actuation with the same peak magnetic strength. The simulated flow structures of the AC power actuation agree well with the experimental visualization, and are similar to those produced by DC power. The AC and DC power actuated flow fields exhibited no significant differences. This numerical study suggests approaches to maximize the performance of the proposed rapid magnetic microfluidic mixer, and confirms its exciting potential for use in lab-on-a-chip systems. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Wang J.-J.,National Cheng Kung University |
Mak O.-T.,National Cheng Kung University |
Mak O.-T.,University of Kang Ning
Prostaglandins and Other Lipid Mediators | Year: 2011
Cyclopentenone prostaglandin 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), which is generated from the dehydration of PGD2, is a natural ligand of peroxisome proliferator-activated receptor gamma (PPARγ) and a potential apoptotic mediator. The synthetic PPARγ ligands, troglitazone and ciglitazone, inhibit tumor progression in many cells by PPARγ activation, but the mechanism of 15d-PGJ2 is still unclear. In this study, GW9662, an antagonist of PPARγ, and quercetin, a natural antioxidant, were used to study the apoptotic mechanism of 15d-PGJ2 in A549 cells. Results showed that 15d-PGJ2 induced apoptosis, which was associated with the production of reactive oxygen species (ROS) and the decrease of GSH levels. Furthermore, quercetin reduced the activity of caspases in 15d-PGJ2-induced apoptotic processes. These results suggest that 15d-PGJ2 induces apoptosis in A549 cells mainly through the formation of ROS; it does not depend on PPARγ activation. Moreover, these findings support the use of quercetin and PPARγ agonists in non-small cell lung carcinoma. © 2011 Elsevier Inc.
Weng C.-J.,University of Kang Ning
Materials Science in Semiconductor Processing | Year: 2010
As design rules for interconnection tend to result in the reduction of silicon chip size, devices have been miniaturized and fabrication processes have become more complex. Implementation of Cu and low dielectric constant (low-k) materials in the manufacturing process integration require a complete understanding of these process characteristics and the challenges that appear during the hard mask based dual damascene approach. To create highly reliable electrical interconnects, the interfaces between the Cu metal and low-k must be optimized during the lithography, etching, ashing and copper processes. For higher aspect ratios interconnect profiles, however this approach leads to increased sidewall roughness and undercut. To suppress problems in the fabrication processes, the balance of the processes integration should be quantitatively and instantaneously controlled to the optimum manufacturing technologies. These process characteristics and manufacturing mechanism optimization will also be discussed. © 2010 Elsevier Ltd. All rights reserved.
Kao S.-F.,University of Kang Ning
Ethics in Science and Environmental Politics | Year: 2012
This article examines the controversy concerning the emission of electromagnetic waves at a meteorological radar site in Chigu, Taiwan, as an example of an emerging technological risk. At the heart of this controversy is a lack of scientific evidence and consensus regarding potential or future effects of the radiation on human health. The Chigu meteorological radar site started operating in 2000, and medical problems have inexplicably increased in one offshore community adjacent to this radar station since 2006. The community residents have long suspected that such disproportionate medical problems are a result of their daily exposure to electromagnetic waves from this meteorological radar site and now they are calling for this station to be dismantled. The Central Weather Bureau has responded to local residents' protests by claiming that no scientific evidence of such risk exists, according to the criteria set by the Environmental Protection Administration (EPA) in Taiwan and several documents published by the World Health Organization. Environmental activists and local residents have never agreed with such responses and claims. Controversies between both camps continue to fester. Drawing from arguments presented in studies by Funtowicz and Ravetz and the literature on participatory risk governance, the present study employs a qualitative approach, with in-depth interviews and analysis of documentary data, to investigate this case. The research delineates conflicting portrayals and framings of scientific knowledge and risk by technocrats and by civil society. The 'post-normal science' call for democratizing expertise has a critical role in providing a perspective through which a contemporary complex scientific controversy may be better understood in social-political contexts in Taiwan and shed light on better risk governance. © Inter-Research 2012.
Yue C.-D.,University of Kang Ning |
Huang G.-R.,University of Kang Ning
Energy Policy | Year: 2011
Solar energy is widely regarded as a major renewable energy source, which in future energy systems will be able to contribute to the security of energy supply and the reduction of CO 2 emissions. This study combined an evaluation of solar energy resources in Taiwan with land use analysis, which allows the potentials and restrictions of solar energy exploitation resulting from local land use conditions to be considered. The findings unveiled in this study indicate that photovoltaic electricity generation and solar water heating have the potential of producing 36.1 and 10.2TWh of electricity and thermal energy annually in Taiwan, accounting for 16.3% and 127.5% of the total domestic consumption of electricity and energy for household water heating in 2009, respectively. However, the exploited solar photovoltaic power generation in 2009 accounted for only 0.02% of total potential in Taiwan, while the exploited solar water heating accounted for 11.6% of total potential. Market price and investment incentive are the dominant factors that affect market acceptance of solar energy installation in Taiwan. The administrative barriers to the purchase and transmission of electricity generated from renewable energy sources have to be removed before the potential contribution of solar energy can be realized. © 2011 Elsevier Ltd.
Liljestrand J.,The University of Cambodia |
Sambath M.R.,University of Kang Ning
Reproductive Health Matters | Year: 2012
Maternal mortality has been falling significantly in Cambodia since 2005 though it had been stagnant for at least 15 years before that. This paper analyzes the evolution of some major societal and health system factors based on recent national and international reports. The maternal mortality ratio fell from 472 per 100,000 live births in 2000-2005 to 206 in 2006-2010. Background factors have included peace and stability, economic growth and poverty reduction, improved primary education, especially for girls, improved roads, improved access to information on health and health services via TV, radio and cellphones, and increased ability to communicate with and within the health system. Specific health system improvements include a rapid increase in facility-based births and skilled birth attendance, notably investment in midwifery training and numbers of midwives providing antenatal care and deliveries within an expanding primary health care network, a monetary incentive for facility-based midwives for every live birth conducted, and an expanding system of health equity funds, making health care free of cost for poor people. Several major challenges remain, including post-partum care, family planning, prevention and treatment of breast and cervical cancer, and addressing sexual violence against women, which need the same priority attention as maternity care. © 2012 Reproductive Health Matters.
Lee T.-L.,University of Kang Ning
Open Civil Engineering Journal | Year: 2010
In this paper, the application of the Fuzzy Analytic Hierarchy Process (Fuzzy AHP) combined with a set of criteria analysis for the selection of appropriate sites for the development offshore wind energy in Taiwan is presented. The Fuzzy AHP was first conducted to rank the importance and identify the key factors of offshore wind energy successfully. From the numerical results, eight key factors that must be considered in the site selection of offshore wind energy system in Taiwan were obtained by using Fuzzy AHP model. They are: wind power, earthquakes, land use, shore type, typhoon, distance to shoreline, flight safety and water depth. Based on these factors, a set of criteria for the selection of sites for offshore wind farms was also established using five different sites in Taiwan. From the assessment results, it was found that Changhua coastal region is an appropriate site for offshore wind energy in Taiwan. © Tsung-Lin Lee.
Hsu K.-J.,University of Kang Ning
2011 International Conference on Multimedia Technology, ICMT 2011 | Year: 2011
Housing sector is one of the important greenhouse gases (GHGs) emissions which result global warming. In order to trace the energy use before and after primary energy factor of electricity adjustment, this paper analyzed the primary energy factor of electricity of the end user in Taiwan from 1982 to 2009 first. Then the compositions of the primary energy use and emissions in Taiwan housing sector were analyzed. The share of electricity use in total energy use of the housing sector was 64.2% at 2009 before primary energy factor of electricity adjustment. By using primary energy factor of the electricity demand of the year as adjustment, the share of the primary energy use of the electricity increased as 84.4%. Results of the research also showed that the annual log growth rate of the primary energy use induced by electricity use was 6.45% in Taiwan housing sector from 1982 to 2009. The total primary energy use of the housing sector in 2009 was about 5.7 times of which in 1982. Respect to emission factor of the housing sector, the research showed that the annual log growth rate of GHG Emissions of the housing sector was 7.81% from 1982 to 2009. The total GHG Emissions of the housing sector in 2009 was about 8.25 times of which in 1982. The shares of emissions from electricity in housing sector were 59.6% in 1982, and 86.6% in 2009. These results showed that the use of electricity was one of the major sources of the housing emissions growth this period. © 2011 IEEE.
Hsu K.-J.,University of Kang Ning
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011 - Proceedings | Year: 2011
This paper examines the sources and paths of greenhouse gases (GHGs) emissions of Taiwan electricity generation 1982-2009. The components of the electricity production were analyzed by applying factorial decomposition method. The model regarding the linkage between primary energy use, economic output and GHGs emissions intensity of electricity generation of Taiwan are derived. The major effects of the emissions include economic output effect, electricity intensity, thermal power shares effect, and emissions intensity of thermal power. Results of the fuel input of the thermal power analysis also showed that the fuel generation mix effect is the major component of the emissions. The fuel input efficiency factors, fuel input per kWh, have negative effect on emissions intensity of the thermal electricity, but the effect is small. In order to sustain the economic performances of Taiwan social/economic needs, low carbon technologies like renewables or energy efficiency should be developed in the future. © 2011 IEEE.
Hsu K.-J.,University of Kang Ning
WIT Transactions on Ecology and the Environment | Year: 2010
State-of-the-art economic analyses of renewable energy technologies (RETs) include using portfolio theory in renewable energy policy planning and using Monte-Carlo simulation to attain the risk profile of the technologies. Most economic analyses now co-list the risk index and GWP index as results of research/policy planning reports. After examining the variants of economic models for RETs, the risk dimensions of traditional energies and RETs were compared. The asymmetry risks allocated between traditional energy and RETs were shown. Combining these asymmetry risk allocations, a project-based RETs financial feasibility model which simultaneously integrates cost and risk information with respect to renewable and traditional energy technologies, was developed. Results of the analysis showed that the risk premium of traditional energies should include the effects of the escalation and volatility of fuel prices. On a national/regional level, the subsidy of fossil fuels for traditional energy production, which is embedded in the economic development policy, should be recovered and the degree to which investment of RETs improved the efficiency of cost-risk portfolio should be measured. On a project-based level, the effect of fuel price escalation and the saving of cost of risk-mitigation should be included.