Iron-based chemical looping processes

Chemical looping technology has attracted significant attention due to its potential in cost-effective CO2 capture capabilities. It utilizes metal oxide as oxygen carriers to indirectly convert carbonaceous fuel such as coal, natural gas and biomass into electricity, H2, liquid fuel without the use of an air separation unit (ASU). In the case of power production, chemical looping process allows for high exergy efficiency, as the high grade heat produced from the oxidation of the oxygen carrier can be extracted for steam production, while the lower grade heat is recuperated in the oxygen carrier to perform its endothermic reduction. With the exponential growth of research and publications in this field, chemical looping has expanded to encompass both power and chemical production with in-situ gas separation. Extensive computational and experimental studies on iron-based composite material support the long-term recyclability, reactivity and physical strength of OSU’s oxygen carriers. In addition, the behavior of iron-based composite material at the micro- and nanoscale will be discussed in the context of optimal oxygen carrier candidates. Nanostructure formation mechanism and ionic diffusion play a central role in sustaining the reactivity and recyclability of Fe-Ti system. OSU’s unique moving-bed chemical looping technology takes full advantage of iron-based oxygen carriers when compared with fluidized-bed system. The synergetic effect between reactor design and oxygen carrier optimization ensures complete fuel conversion and near 100% CO2 capture. To date, more than 1000 operating hours have been achieved in 25-kWth sub-pilot scale unit with coal, biomass and syngas at the OSU Clean Energy Research Center. Near 100% conversion of both gaseous and solid fuel types to CO2 were achieved. A 250 kWth-3MWth syngas chemical looping pilot scale demonstration is currently in its testing phase at the National Carbon Capture Center. The present paper summarizes key results and development for both the syngas chemical looping and coal direct chemical looping systems

MATEX: A Distributed Framework for Transient Simulation of Power Distribution Networks

We proposed MATEX, a distributed framework for transient simulation of power distribution networks (PDNs). MATEX utilizes matrix exponential kernel with Krylov subspace approximations to solve differential equations of linear circuit. First, the whole simulation task is divided into subtasks based on decompositions of current sources, in order to reduce the computational overheads. Then these subtasks are distributed to different computing nodes and processed in parallel. Within each node, after the matrix factorization at the beginning of simulation, the adaptive time stepping solver is performed without extra matrix re-factorizations. MATEX overcomes the stiff-ness hinder of previous matrix exponential-based circuit simulator by rational Krylov subspace method, which leads to larger step sizes with smaller dimensions of Krylov subspace bases and highly accelerates the whole computation. MATEX outperforms both traditional fixed and adaptive time stepping methods, e.g., achieving around 13X over the trapezoidal framework with fixed time step for the IBM power grid benchmarks.Comment: ACM/IEEE DAC 2014. arXiv admin note: substantial text overlap with arXiv:1505.0669

Containership Flag Selection: The Opening of Direct Shipping between Taiwan and China

The signature of the cross-strait sea transport (CST) Agreement in 2008 has not only established the cross-strait direct shipping link, but also lifted the ban on the involvement of Taiwanese flagged ships to call at China’s ports. This paper focuses on the flag selection for Taiwanese container shipping companies under the provisions of the CST Agreement, and embraces the empirical investigation based on the Analytic Hierarchy Process (AHP) and Grey Relation Analysis (GRA) with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The results show Hong Kong is the optimal choice rather than China and Taiwan. Although cross-strait shipping is highly controlled by both sides of the strait, economic factors are still taken seriously in commercial activities. Further, to assist shipping companies to get direct shipping approvals from China and revising a package of financial measures under current shipping policies are recommended for the Taiwanese government

An exact single-agent task selection algorithm for the crowdsourced logistics

Agency for Science, Technology and Research (A*STAR); Fujitsu; National Research Foundation (NRF) Singapor

SPATIAL EQUILIBRIUM MODELING WITH IMPERFECTLY COMPETITIVE MARKETS: AN APPLICATION TO RICE TRADE

A general imperfect competition spatial equilibrium model is developed to estimate the trading country behaviors in the international rice market using a conjectural variation approach. Such a model allows the possibility of an imperfect competitive market to exit on both the export and import sides without any assumption of market structure. The empirical results show that the major exporting countries, Thailand, Vietnam, and the U.S. acted as high degree of imperfect competitors(or oligopolies) while Pakistan acted as a lower degree of imperfect competitor. The importing countries such as Japan, the Philippines, Europe, Brazil, and the former USSR behaved as high degree of imperfect competitors (or oligopsonies). The empirical results also show that there are welfare gains of $1,492 million when all trading countries comply with the free trade agreement.Marketing,

THE VARIATION OF DOMINANT ELBOW RANGE OF MOTION AMONG DIFFERENT MATURE STAGE FOR BASEBALL PITCHERS

The purpose of this study was to examine the variation of elbow range of motion (ROM) in the dominant arm between different maturity levels in baseball pitchers. Sixty-two pitchers, including 17 early-puberty players, 22 later-puberty players, and 23 adult players, participated in this study. A goniometer was used to assess elbow ROM in the dominant arms, including elbow flexion, hyper-extension, supination, pronation and valgus angles. The results showed that smaller ROM was found in elbow flexion, supination, and pronation, and larger ROM in elbow valgue, in pithers of later puberty level (

THE RELATIONSHIP BETWEEN SHOULDER PAIN AND SCAPULAR MOBILITY IN TEENAGE BASEBALL PLAYERS

The purpose of this study was to identify the relationship between shoulder pain and scapular mobility for teenage baseball players. Thirty-five teenage baseball players (shoulder pain, n=11; healthy, n=24) were recruited in this study. The lateral scapula slide test (LSST), which represented as scapular mobility, was used to measure the scapular position and symmetry under varying loads. The result of this study showed that there was a difference in distance from the superior angle of the scapula to the spinous process of T2 between the two groups at shoulder 90?abduction

Septic Shock after Conservative Management for Placenta Accreta

SummaryObjectiveThe rate of placenta accreta has risen in the last three decades due to the increasing rate of cesarean section. Placenta accreta usually results in severe postpartum hemorrhage requiring massive blood transfusion and postpartum hysterectomy. Conservative treatment is an alternative in selected patients to preserve fertility and decrease postpartum hemorrhage, but the risks of conservative treatment have seldom been described.Case ReportA 39-year-old woman with placenta accreta diagnosed during cesarean section was treated conservatively. Persistent puerperal fever with leukocytosis developed during the postpartum period in spite of long-term antibiotic treatment. Evacuation of the retained placenta resulted in septic shock, which occurred immediately after dilatation and curettage. An uneventful recovery was achieved after use of strong antibiotics and fluid challenge.ConclusionAt present, there is no consensus about the optimal treatment for placenta accreta. Conservative treatment appears to be an alternative in selected patients, but the complications such as sepsis should be carefully identified and appropriately managed