Non-Nuclear, Low-Carbon, or Both? The Case of Taiwan

The Fukushima nuclear accident in Japan has renewed debates on the safety of nuclear power, possibly hurting the role of nuclear power in efforts to limit CO2 emissions. I develop a dynamic economy-wide model of Taiwan with a detailed set of technology options in the power sector to examine the implications of adopting different nuclear power policies on CO2 emissions and the economy. Absent a carbon mitigation target, limiting nuclear power has a small economic cost for Taiwan, but CO2 emissions may increase by more than 3.5% by 2035 when nuclear is replaced by fossil-based generation. With a low-carbon target of a 50% reduction from year 2000 levels by 2050, if the nuclear option and carbon sequestration are not viable, gas-fired power would provide almost 90% of electricity output due to the limited renewable resources. In particular, wind power would account for 1.6% to 4.9% of that output, depending on how it relies on other back-up capacities. With both non-nuclear and low-carbon policies, deploying carbon sequestration on fossil-based generation can significantly reduce the negative GDP impact on the economy. Lastly, lowering carbon mitigation costs further is possible with expanded nuclear capacity.The author gratefully acknowledges comments and suggestions from John Reilly, Frank Hsiao, Audrey Resutek, and seminar participants of the MIT EPPA meeting, and the financial support from the MIT Joint Program on the Science and Policy of Global Change. The Program is funded by the following institutions under various grants: the U.S. Department of Energy; the U.S. Environmental Protection Agency; the U.S. National Science Foundation; the U.S. National Aeronautics and Space Administration; the U.S. National Oceanic and Atmospheric Administration; the U.S. Federal Aviation Administration; the Electric Power Research Institute; and a consortium of industrial and foundation sponsors (for complete list see http://globalchange.mit.edu/sponsors/all)

Labeled Partitions with Colored Permutations

In this paper, we extend the notion of labeled partitions with ordinary permutations to colored permutations in the sense that the colors are endowed with a cyclic structure. We use labeled partitions with colored permutations to derive the generating function of the $\mathrm{fmaj}_k$ indices of colored permutations. The second result is a combinatorial treatment of a relation on the q-derangement numbers with respect to colored permutations which leads to the formula of Chow for signed permutations and the formula of Faliharimalala and Zeng [10] on colored permutations. The third result is an involution on permutations that implies the generating function formula for the signed q-counting of the major indices due to Gessel and Simon. This involution can be extended to signed permutations. In this way, we obtain a combinatorial interpretation of a formula of Adin, Gessel and Roichman.Comment: 14 page

A rate-insensitive linear viscoelastic model for soft tissues

It is well known that many biological soft tissues behave as viscoelastic materials with hysteresis curves being nearly independent of strain rate when loading frequency is varied over a large range. In this work, the rate-insensitive feature of biological materials is taken into account by a generalized Maxwell model. To minimize the number of model parameters, it is assumed that the characteristic frequencies of Maxwell elements form a geometric series. As a result, the model is characterized by five material constants: micro(0), tau, m, rho and beta, where micro(0) is the relaxed elastic modulus, tau the characteristic relaxation time, m the number of Maxwell elements, rho the gap between characteristic frequencies, and beta=micro(1)/micro(0) with micro(1) being the elastic modulus of the Maxwell body that has relaxation time tau. The physical basis of the model is motivated by the microstructural architecture of typical soft tissues. The novel model shows excellent fit of relaxation data on the canine aorta and captures the salient features of vascular viscoelasticity with significantly fewer model parameters

The Prospects for Coal-To-Liquid Conversion: A General Equilibrium Analysis

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).We investigate the economics of coal-to-liquid (CTL) conversion, a polygeneration technology that produces liquid fuels, chemicals, and electricity by coal gasification and Fischer-Tropsch process. CTL is more expensive than extant technologies when producing the same bundle of output. In addition, the significant carbon footprint of CTL may raise environmental concerns. However, as petroleum prices rise, this technology becomes more attractive especially in coal-abundant countries such as the U.S. and China. Furthermore, including a carbon capture and storage (CCS) option could greatly reduce its CO2 emissions at an added cost. To assess the prospects for CTL, we incorporate the engineering data for CTL from the U.S. Department of Energy (DOE) into the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium model of the global economy. Based on DOE's plant design that focuses mainly on liquid fuels production, we find that without climate policy, CTL has the potential to account for up to a third of the global liquid fuels supply by 2050 and at that level would supply about 4.6% of global electricity demand. A tight global climate policy, on the other hand, severely limits the potential role of the CTL even with the CCS option, especially if low-carbon biofuels are available. Under such a policy, world demand for petroleum products is greatly reduced, depletion of conventional petroleum is slowed, and so the price increase in crude oil is less, making CTL much less competitive.BP-MIT Conversion Research Project. U.S. Department of Energy, Environmental Protection Agency, and by a consortium of industry and foundation sponsors

Canada’s Bitumen Industry Under CO2 Constraints

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).We investigate the effects of implementing CO2 emissions reduction policies on Canada’s oil sands industry, the largest of its kind in the world. The production of petroleum products from oils sands involves extraction of bitumen from the oil sands, upgrading it to a synthetic crude oil by adding lighter hydrocarbons, and then use of more conventional petroleum refining processes to create products such as gasoline and diesel. The relatively heavy crude generally requires the use of cracking and other advanced refinery operations to generate a product slate with substantial fractions of the higher value petroleum products such as diesel and gasoline. Each part of the process involves significant amounts of energy, and that contributes to a high level of CO2 emissions. We apply the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium model of the world economy, augmented to include detail on the oil sands production processes, including the possibility of carbon capture and storage (CCS). We find: (1) without climate policy annual Canadian bitumen production increases over 6-fold from 2005 to 2050; (2) with CO2 emissions caps implemented in developed countries, Canadian bitumen production drops by nearly 65% from the reference 6-fold increase and bitumen upgrading capacity moves to the developing countries; (3) with CO2 emissions caps implemented worldwide, the Canadian bitumen production becomes essentially non-viable even with CCS technology, at least through our 2050 horizon. The main reason for the demise of the oil sands industry with global CO2 policy is that the demand for oil worldwide drops substantially. CCS takes care of emissions from the oil sands production, upgrading, and refining processes, at a cost, but there is so little demand for petroleum products which still emit CO2 when used that it can be met with conventional oil resources that entail less CO2 emissions in the production process.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors

Beyond Same Sex Attraction: Gender Variant Based Victimization is Associated with Suicidal Behavior and Substance Use for Other Sex Attracted Adolescents

Gender-variant-based victimization is victimization based on the way others perceive an individual to convey masculine, feminine, and androgynous characteristics through their appearance, mannerisms, and behaviors. Previous work identifies gender-variant-based victimization as a risk factor for health-risking outcomes among same-sex attracted youths. The current study seeks to examine this relationship among other-sex attracted youths and same-sex attracted youth, and determine if gender-variant-based victimization is similarly or differentially associated with poor outcomes between these two groups. Anonymous data from a school-based survey of 2,438 racially diverse middle and high school students in the Eastern U.S. was examined. For other-sex attracted adolescents, gender-variantbased victimization was associated with a higher odds of suicidal thoughts and behaviors, regular use of cigarettes, and drug use. When compared to same-sex attracted adolescents, the harmful relationship between gender-variant-based victimization and each of these outcomes was similar in nature. These findings suggest that gender-variant-based victimization has potentially serious implications for the psychological wellbeing and substance use of other-sex attracted adolescents, not just same-sex attracted adolescents, supporting the need to address gender expression as a basis for victimization separate from sexuality- or gender-minority status. The impact that gender-variant-based victimization has on all adolescents should not be overlooked in research and interventions aimed at addressing sexual orientation-based and gender-variant-based victimization, substance use, and suicide prevention

Satellite-based delivery of educational content to geographically isolated communities: A service based approach

Enabling learning for members of geographically isolated communities presents benefits in terms of promoting regional development and cost savings for governments and companies. However, notwithstanding recent advances in e-Learning, from both technological and pedagogical perspectives, there are very few, if any, recognised methodologies for user-led design of satellite-based e-learning infrastructures. In this paper, we present a methodology for designing a satellite and wireless based network infrastructure and learning services to support distance learning for such isolated communities. This methodology entails (a) the involvement of community members in the development of targeted learning services from an early stage, and (b) a service-oriented approach to learning solution deployment. Results show, that, while the technological premises of distance learning can be accommodated by hybrid satellite/wireless infrastructures,this has to be complemented with (a) high-quality audio–visual educational material, and (b) the opportunity for community members to interact with other community members either as groups (common-room oriented scenarios) or individuals (home-based scenarios), thus providing an impetus for learner engagement in both formal and informal activities

Microscopic Delineation of Medulloblastoma Margins in a Transgenic Mouse Model Using a Topically Applied VEGFR-1 Probe

AbstractThe unambiguous demarcation of tumor margins is critical at the final stages in the surgical treatment of brain tumors because patient outcomes have been shown to correlate with the extent of resection. Real-time high-resolution imaging with the aid of a tumor-targeting fluorescent contrast agent has the potential to enable intraoperative differentiation of tumor versus normal tissues with accuracy approaching the current gold standard of histopathology. In this study, a monoclonal antibody targeting the vascular endothelial growth factor receptor 1 (VEGFR-1) was conjugated to fluorophores and evaluated as a tumor contrast agent in a transgenic mouse model of medulloblastoma. The probe was administered topically, and its efficacy as an imaging agent was evaluated in vitro using flow cytometry, as well as ex vivo on fixed and fresh tissues through immunohistochemistry and dual-axis confocal microscopy, respectively. Results show a preferential binding to tumor versus normal tissue, suggesting that a topically applied VEGFR-1 probe can potentially be used with real-time intraoperative optical sectioning microscopy to guide brain tumor resections

Primordial Trispectrum from Entropy Perturbations in Multifield DBI Model

We investigate the primordial trispectra of the general multifield DBI inflationary model. In contrast with the single field model, the entropic modes can source the curvature perturbations on the super horizon scales, so we calculate the contributions from the interaction of four entropic modes mediating one adiabatic mode to the trispectra, at the large transfer limit ($T_{RS}\gg1$). We obtained the general form of the 4-point correlation functions, plotted the shape diagrams in two specific momenta configurations, "equilateral configuration" and "specialized configuration". Our figures showed that we can easily distinguish the two different momenta configurations.Comment: 17pages, 7 figures, version to appear in JCA