A Nonlinear Non-dimensional Dynamic Model for Free Piston Thermal-lag Stirling Engine

AbstractThis study is aimed to develop a theoretical model to determine criterion of instability and predict performance of a free-piston thermal-lag Stirling engine (FPTLSE). Experiments are conducted to verify the theoretical predictions partly. In the present study, a nonlinear model consisting of non-dimensional equation of motion and energy equation are derived. These governing equations are solved simultaneously by employing a multi-scale method, in which zero-order approximate solutions representing piston motion and temperature variation are obtained. Results show that the FPTLSE can be a self-started engine that may be able to start automatically after heating. In addition, the predictions by the theoretical model are found to agree closely with the experimental data for the oscillation of the piston. The present model is capable of predicting the dynamic behavior of the engine

The International Decision-Making and Travel Behavior of Graduates Participating in Working Holiday

After graduation, most graduates find themselves at a significant stage in their life as they have to decide between “further study” and “working.” When faced with this confusion and uncertainty, a “working holiday” combining travel and work has coincidentally becomes a third option. This study employed a qualitative approach through literature review, in-depth interviews, and semi-structured interviews. The research revealed that graduates are influenced by “internal personal thinking” and “external driving forces” when they embark on a working holiday. The former includes negative obstructions and positive stimulus. The latter factor’s stimulus includes attraction of natural landscapes, history and culture, learning foreign languages, safety concerns, difficulties in visa application, and the opportunity to obtain a salaried job. The process of embarking on a working holiday was complex and unpredictable. The traveling behavior of working holiday destinations included short-distance leisure behavior and long-distance traveling behavior. In terms of the influences of short-distance leisure behavior, graduates preferred being employed by service industries that had less working hours, flexible work arrangements and included the purchase of preferential price tickets. Graduates’ long-distance traveling behavior was affected by the work they performed. The travel time was different between various industries

Lymphangiomatous macroglossia associated with extensive cervicomediastinal cystic hygromas

AbstractChildren with lymphangiomatous macroglossia often have difficulty eating and talking, and their airways may be compromised because of bleeding and infection, especially when extensive cervicomediastinal cystic hygromas are present. We report a case of lymphangiomatous macroglossia associated with extensive cystic hygromas in the cervicomediastinal region. The 3-year-old girl was treated with anterior wedge reduction of the tongue, needle aspiration of the cervicomediastinal cystic hygromas, and systemic steroids and antibiotics. The extensive cystic cervicomediastinal hygromas spontaneously regressed, and further surgery was not needed until 4 years later. Surprisingly, subtotal or partial lymphatic malformation removal improved the complicated lymphatic malformation

Investigation of Landslides and Debris Flows in Tachia Watershed Between Maan Dam and Techi Dam

The Chi-Chi earthquake and subsequent typhoon events induced severe landslides and debris flows in the watershed of Tachia river. It inflicted severe damage to the power generation facilities and highway links. For the rehabilitation planning, quantitative assessment of landslides, debris flows and river deposits were conducted by using aerial photos and satellite images obtained at six stages of earthquake and typhoon events. The future trends of landslide and debris flow were also investigated by using empirical models. The long-term deposition or scouring was also conducted by numerical simulation. The results show that over 50,000,000 to 70,000,000m3 of sliding volume were induced in the Chi-Chi earthquake and subsequent typhoon events during 1999 to 2005. By conservative estimation, 60% of the debris still remain in the watershed, which will cause silting of the main river channel in the future. The deposition in the main river channel will increase with decreasing rate in the future, and river channel scouring is not expected to occur in the future 20 to 30 years

Differentiation of Foot-and-Mouth Disease-Infected pigs from Vaccinated Pigs Using Antibody-Detecting Sandwich ELISA

The presence of serum antibodies for nonstructural proteins of the foot-and-mouth disease virus (FMDV) can differentiate FMDV-infected animals from vaccinated animals. In this study, a sandwich ELISA was developed for rapid detection of the foot-and-mouth disease (FMD) antibodies; it was based on an Escherichia coli-expressed, highly conserved region of the 3ABC nonstructural protein of the FMDV O/TW/99 strain and a monoclonal antibody derived from the expressed protein. The diagnostic sensitivity of the assay was 98.4%, and the diagnostic specificity was 100% for naïve and vaccinated pigs; the detection ability of the assay was comparable those of the PrioCHECK and UBI kits. There was 97.5, 93.4 and 66.6% agreement between the results obtained from our ELISA and those obtained from the PrioCHECK, UBI and CHEKIT kits, respectively. The kappa statistics were 0.95, 0.87 and 0.37, respectively. Moreover, antibodies for nonstructural proteins of the serotypes A, C, Asia 1, SAT 1, SAT 2 and SAT 3 were also detected in bovine sera. Furthermore, the absence of cross-reactions generated by different antibody titers against the swine vesicular disease virus and vesicular stomatitis virus (VSV) was also highlighted in this assay's specificit

Qubit Mapping Toward Quantum Advantage

Qubit Mapping is a pivotal stage in quantum compilation flow. Its goal is to convert logical circuits into physical circuits so that a quantum algorithm can be executed on real-world non-fully connected quantum devices. Qubit Mapping techniques nowadays still lack the key to quantum advantage, scalability. Several studies have proved that at least thousands of logical qubits are required to achieve quantum computational advantage. However, to our best knowledge, there is no previous research with the ability to solve the qubit mapping problem with the necessary number of qubits for quantum advantage in a reasonable time. In this work, we provide the first qubit mapping framework with the scalability to achieve quantum advantage while accomplishing a fairly good performance. The framework also boasts its flexibility for quantum circuits of different characteristics. Experimental results show that the proposed mapping method outperforms the state-of-the-art methods on quantum circuit benchmarks by improving over 5% of the cost complexity in one-tenth of the program running time. Moreover, we demonstrate the scalability of our method by accomplishing mapping of an 11,969-qubit Quantum Fourier Transform within five hours

IMECE2010-39672 Numerical Analysis of Liquid Water Droplets Removal in Gas Channels of a PEM Fuel Cell

ABSTRACT The present study is concerned with the dynamic behavior of the liquid water droplets in the water removal process in the serpentine channels of a PEM fuel cell based on computational fluid dynamic (CFD) simulation. The volume of fluid (VOF) model is adopted to trace the interface between the liquid and the gas phases such that the motion of the liquid droplets can be observed. Effects of the incoming velocity are evaluated. In addition, the surface hydrophobic properties are influential to the droplets motion; therefore, the contact angle of the liquid droplet attached on the channel wall has been varied. In addition, the orientation of the bipolar plate is regarded as another important parameter in the present study. Results show that among these parameters considered, the incoming flow velocity and the contact angle are two key parameters which greatly affect the dynamic behavior of the liquid droplets. The liquid droplets attached on the wall of the bipolar plate can be removed by the gas flow only when the contact angle or the incoming flow velocity is sufficiently high

Granger causal connectivity dissociates navigation networks that subserve allocentric and egocentric path integration

Studies on spatial navigation demonstrate a significant role of the retrosplenial complex (RSC) in the transformation of egocentric and allocentric information into complementary spatial reference frames (SRFs). The tight anatomical connections of the RSC with a wide range of other cortical regions processing spatial information support its vital role within the human navigation network. To better understand how different areas of the navigational network interact, we investigated the dynamic causal interactions of brain regions involved in solving a virtual navigation task. EEG signals were decomposed by independent component analysis (ICA) and subsequently examined for information flow between clusters of independent components (ICs) using direct short-time directed transfer function (sdDTF). The results revealed information flow between the anterior cingulate cortex and the left prefrontal cortex in the theta (4-7 Hz) frequency band and between the prefrontal, motor, parietal, and occipital cortices as well as the RSC in the alpha (8-13 Hz) frequency band. When participants prefered to use distinct reference frames (egocentric vs. allocentric) during navigation was considered, a dominant occipito-parieto-RSC network was identified in allocentric navigators. These results are in line with the assumption that the RSC, parietal, and occipital cortices are involved in transforming egocentric visual-spatial information into an allocentric reference frame. Moreover, the RSC demonstrated the strongest causal flow during changes in orientation, suggesting that this structure directly provides information on heading changes in humans