Enhancing the learning experience- Use of video game technology for teaching Japanese language

The Japanese language is challenging to learn, especially for native speakers of Indo- European languages. The three components of written Japanese -- Hiragana, Katakana, and Kanji – include 2,136 Kanji characters, and 46 each for Katakana and Hiragana. Teaching Japanese – generally through repetition – can lead to student boredom and affect success. Research shows that video games can at least provide a more enjoyable learning experience. Despite this fact, there are a lack of video games for teaching Japanese characters. Using the Unity game engine and the C# programming language, a video game for enhancing the learning of students studying Japanese as a second language was created. Users must identify the Japanese characters as they trickle from top to bottom on the screen. The more times the user identifies a particular Japanese character, the less that character will appear. The reverse applies to incorrect answers – the character will appear more often. This is a key learning technique as the user is forced to repeat those characters he/she does not know. This project demonstrates that the dearth of available, effective video games to complement foreign language learning can be overcome. Basic programming skills combined with some creative design, and a strong desire to help others learn, can result in simple but effective video games. The interactive experience will certainly improve students’ ability to learn this challenging language

Computational Fluid Dynamics in Congenital Heart Disease

Computational fluid dynamics has been applied to the design, refinement, and assessment of surgical procedures and medical devices. This tool calculates flow patterns and pressure changes within a virtual model of the cardiovascular system. In the field of paediatric cardiac surgery, computational fluid dynamics is being used to elucidate the optimal approach to staged reconstruction of specific defects and study the haemodynamics of the resulting anatomical configurations after reconstructive or palliative surgery. In this paper, we review the techniques and principal findings of computational fluid dynamics studies as applied to a few representative forms of congenital heart disease

Interpretation of Binary Pulsar Observations

The nature, dynamics and evolution of the three known radio pulsar binaries are discussed. The system containing 1913+16 appears to comprise two ~1.4 M⊙ components, and to undergo orbital decay as predicted by general relativity. It is proposed that 1913+16 has a neutron star companion and that 0655+64 and 0820+02 have white dwarf companions which should be observable optically

Evaluation of Stent and Baffle Deformation in Hybrid Comprehensive Stage II Procedure

Introduction: Hypoplastic Left Heart Syndrome (HLHS) is a Congenital Heart Disease (CHD) that leads to a single ventricle circulation (SV). The existing three-stage palliative operation leads to 50% survival rates. To reduce the morbidity and mortality rate associated with the procedure, an alternative technique called Hybrid Comprehensive Stage II (HCSII) featuring the inclusion of a stent and baffle in the left and right pulmonary arteries shown is proposed. The included stent included has the potential to become fractured as a result of oscillatory asymmetric external loads. Materials and Methods: A dynamically-scaled mock flow loop (MFL) study of HCSII shows the effects of fluid pressure on the stent and baffle to infer long term complications validated with numerical simulations. The MFL includes a patient-specific 3D printed model of the reconstructed anatomy, incorporating an intra-pulmonary baffle graft and a stent. Through the inclusion of the digital video otoscope DE500, videos of the stent and baffle are captured and post-processed to determine baffle displacement during the systolic and diastolic phases. Stent deformation is quantified using Scanning Electron Microscope (SEM).Experimental results are cross-validated, using finite element analysis done in Abaqus. Results and Discussion: The displacement of the baffle is tracked in three different locations throughout the cycles. Between peak systole to peak diastole, the computed baffle displacement for each tracked location, based on the processed image data, is 38, 4 and 6 pixels respectively. Conclusions: For 10 cycles, the stent and the baffle deformations are small. Results indicate the left and right pulmonary flow remain unobstructed despite cyclic deformation of the baffle, hence the likelihood of patient death due to total pulmonary obstruction following stent collapse is low

Metallicity of the Massive Protoplanets Around HR 8799 If Formed by Gravitational Instability

The final composition of giant planets formed as a result of gravitational instability in the disk gas depends on their ability to capture solid material (planetesimals) during their 'pre-collapse' stage, when they are extended and cold, and contracting quasi-statically. The duration of the pre-collapse stage is inversely proportional roughly to the square of the planetary mass, so massive protoplanets have shorter pre-collapse timescales and therefore limited opportunity for planetesimal capture. The available accretion time for protoplanets with masses of 3, 5, 7, and 10 Jupiter masses is found to be 7.82E4, 2.62E4, 1.17E4 and 5.67E3 years, respectively. The total mass that can be captured by the protoplanets depends on the planetary mass, planetesimal size, the radial distance of the protoplanet from the parent star, and the local solid surface density. We consider three radial distances, 24, 38, and 68 AU, similar to the radial distances of the planets in the system HR 8799, and estimate the mass of heavy elements that can be accreted. We find that for the planetary masses usually adopted for the HR 8799 system, the amount of heavy elements accreted by the planets is small, leaving them with nearly stellar compositions.Comment: accepted for publication in Icaru

Computational Analysis of Hybrid Norwood Circulation with Distal Aortic Arch Obstruction and Reverse Blalock-Taussig Shunt

BACKGROUND: The hemodynamics characteristics of the hybrid Norwood (HN) procedure differ from those of the conventional Norwood and are not fully understood. We present a multi-scale model of HN circulation to understand local hemodynamics and effects of aortic arch stenosis and a reverse Blalock-Taussig shunt (RBTS) on coronary and carotid perfusion. METHODS: Four 3-dimensional models of four HN anatomic variants were developed, with and without 90% distal preductal arch stenosis and with and without a 4-mm RBTS. A lumped parameter model of the circulation was coupled to a local 3-dimensional computational fluid dynamics model. Outputs from the lumped parameter model provided waveform boundary conditions for the computational fluid dynamics model. RESULTS: A 90% distal arch stenosis reduced pressure and net flow-rate through the coronary and carotid arteries by 30%. Addition of the RBTS completely restored pressure and flow rate to baseline in these vessels. Zones of flow stagnation, flow reversal, and recirculation in the presence of stenosis were rendered more orderly by addition of the RBTS. In the absence of stenosis, presence of the shunt resulted in extensive zones of disturbed flow within the RBTS and arch. CONCLUSIONS: We found that a 4-mm × 21-mm RBTS completely compensated for the effects of a 90% discrete stenosis of the distal aortic arch in the HN. Placed preventatively, the RBTS and arch displayed zones with thrombogenic potential showing recirculation and stagnation that persist for a substantial fraction of the cardiac cycle, indicating that anticoagulation should be considered with a prophylactic RBTS

Emission-line profile modelling of structured T Tauri magnetospheres

We present hydrogen emission line profile models of magnetospheric accretion onto Classical T Tauri stars. The models are computed under the Sobolev approximation using the three-dimensional Monte Carlo radiative-transfer code TORUS. We have calculated four illustrative models in which the accretion flows are confined to azimuthal curtains - a geometry predicted by magneto-hydrodynamical simulations. Properties of the line profile variability of our models are discussed, with reference to dynamic spectra and cross-correlation images. We find that some gross characteristics of observed line profile variability are reproduced by our models, although in general the level of variability predicted is larger than that observed. We conclude that this excessive variability probably excludes dynamical simulations that predict accretion flows with low degrees of axisymmetry.Comment: 14 pages, 12 figures. Published in MNRA

The X-ray puzzle of the L1551 IRS 5 jet

Protostars are actively accreting matter and they drive spectacular, dynamic outflows, which evolve on timescales of years. X-ray emission from these jets has been detected only in a few cases and little is known about its time evolution. We present a new Chandra observation of L1551 IRS 5's jet in the context of all available X-ray data of this object. Specifically, we perform a spatially resolved spectral analysis of the X-ray emission and find that (a) the total X-ray luminosity is constant over almost one decade, (b) the majority of the X-rays appear to be always located close to the driving source, (c) there is a clear trend in the photon energy as a function of the distance to the driving source indicating that the plasma is cooler at larger distances and (d) the X-ray emission is located in a small volume which is unresolved perpendicular to the jet axis by Chandra. A comparison of our X-ray data of the L1551 IRS 5 jet both with models as well as X-ray observations of other protostellar jets shows that a base/standing shock is a likely and plausible explanation for the apparent constancy of the observed X-ray emission. Internal shocks are also consistent with the observed morphology if the supply of jet material by the ejection of new blobs is sufficiently constant. We conclude that the study of the X-ray emission of protostellar jet sources allows us to diagnose the innermost regions close to the acceleration region of the outflows.Comment: A&A accepted, 14 pages, 9 figure