Naresuan University Journal
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FPGA Hardware Acceleration of Monte Carlo Simulations for the Ising Model
No full textA two-dimensional Ising model with nearest-neighbors ferromagnetic interactions is implemented in a Field Programmable Gate Array (FPGA) board. Extensive Monte Carlo simulations were carried out using an efficient hardware representation of individual spins and a combined global-local LFSR random number generator. Consistent results regarding the descriptive properties of magnetic systems, like energy, magnetization and susceptibility are obtained while a speed-up factor of approximately six times is achieved in comparison to previous FPGA-based published works and almost 10^4 times in comparison to a standard CPU simulation. A detailed description of the logic design used is given together with a careful analysis of the quality of the random number generator used. The obtained results confirm the potential of FPGAs for analyzing the statistica
A Strain Energy Approach for Predicting Keyway Root Cracking of an AGR Graphite Brick
No full textThe graphite components in an advanced gas-cooled reactor (AGR) core are subjected to fast neutron irradiation, thermal gradients and radiolytic oxidation during the reactor operation. The non-uniform changes in the material properties, irradiation, temperature, and weight loss across a typical graphite moderator brick lead to the generation of significant internal stresses. The internal stresses in a typical moderator brick are tensile at the bore and compressive at the periphery in early life, but later in life the stresses are reversed resulting in tensile stress at the periphery. The presence of sharp near 90° corners (keyway roots) at the brick periphery lead to stress concentrations and possible sites for crack initiation. Unirradiated graphite is a quasi-brittle material that becomes more brittle with increased irradiation. Sharp corners and notches, such as the brick keyways, are stress raisers as the stresses are singular at the notch/corner tip. This is similar to the singularity observed at a crack tip, which needs to be accounted for using fracture mechanics parameters such as the stress intensity factors (SIFs) in finite element assessments. Similarly, notch stress intensity factors (NSIFs) can be used to predict crack initiation at a 90o corner tip; i.e. crack initiation occurs when the NSIF reaches a critical value. In this paper, a local approach based on strain energy is explored and developed to predict the NSIF values at the keyway roots of an AGR moderator brick. The predicted NSIF values provide an alternative local failure criterion at the keyway roots based on fracture mechanics compared with the current criterion which is based on a series of failure stresses derived from feature tests for various loading configurations. One of the main advantages of this new methodology is that the criteria are not load geometry dependent and can be applied at any of the keyways
Refining prognosis and identifying targetable pathways for high-risk endometrial cancer; a TransPORTEC initiative
No full textThis study aimed to investigate whether molecular analysis can be used to refine risk assessment, direct adjuvant therapy, and identify actionable alterations in high-risk endometrial cancer. TransPORTEC, an international consortium related to the PORTEC3 trial, was established for translational research in high-risk endometrial cancer. In this explorative study, routine molecular analyses were used to detect prognostic subgroups: p53 immunohistochemistry, microsatellite instability and POLE proofreading mutation. Furthermore, DNA was analyzed for hotspot mutations in 13 additional genes (BRAF, CDKNA2, CTNNB1, FBXW7, FGFR2, FGFR3, FOXL2, HRAS, KRAS, NRAS, PIK3CA, PPP2R1A, and PTEN) and protein expression of ER, PR, PTEN, and ARID1a was analyzed. Rates of distant metastasis, recurrence-free, and overall survival were calculated using the Kaplan-Meier method and log-rank test. In total, samples of 116 high-risk endometrial cancer patients were included: 86 endometrioid; 12 serous; and 18 clear cell. For endometrioid, serous, and clear cell cancers, 5-year recurrence-free survival rates were 68%, 27%, and 50% (P=0.014) and distant metastasis rates 23%, 64%, and 50% (P=0.001), respectively. Four prognostic subgroups were identified: (1) a group of p53-mutant tumors; (2) microsatellite instable tumors; (3) POLE proofreading-mutant tumors; and (4) a group with no specific molecular profile (NSMP). In group 3 (POLE-mutant; n=14) and group 2 (microsatellite instable; n=19) patients, no distant metastasis occurred, compared with 50% distant metastasis rate in group 1 (p53-mutant; n=36) and 39% in group 4 (NSMP;
Mechanical Properties of 3D Printed Facial Prostheses compared to Handmade Silicone Polymer Prostheses
No full textPurpose: To evaluate the mechanical properties of the 3D printed starch models infiltrated with maxillofacial silicone polymers used for fabrication of maxillofacial prostheses compared to the mechanical properties of pure silicone polymer models. Materials and methods: The test and control specimens were designed according to industry standards ASTM specifications using SolidWorks 2008 software for testing tensile strength tear strength, percentage elongation and hardness properties of starch infiltrated silicone polymer. Ten Dumbbell-shaped specimens and ten Trousershaped specimens with four hardness test specimens were printed by Zcorp 510 3D printer and infiltrated with Sil-25 maxillofacial silicone polymer. Whereas, control samples made from pure Sil-25 silicone polymers using a stainless steel mould and following a similar specification of test specimens. Lloyd LRX tensile instrument; load rating 100 N at a constant crosshead speed of 25 mm/min for testing tensile, tear strength and percentage elongation and Hardness Tester (England) was used to measure shore A durometer hardness. Results: Silicone polymer infiltrated starch (test) specimens demonstrated significantly lower tensile strength, tear strength and percentage elongation than the pure silicone polymer (control) samples (
An iterative observer approach to harmonic estimation for multiple measurements in power distribution systems
No full textIn the past decade, there has been a significant increase in the use of power electronic components in the design of household and industrial equipment. The use of power electronic based renewable energy resources, electric vehicles and other residential nonlinear loads may result in significant increases in injection levels of harmonics across a power system. Hence, it is important for utility companies to ascertain the exact harmonic levels present in terms of the amplitude and phase of each harmonic order. This paper provides a mathematical basis for distribution system state-space equations to formulate an iterative observer, which can simultaneously estimate harmonics present in a number of measurements taken from the power system. The method not only improves the computation time and provides real-time data for harmonic monitoring, but also performs wide area harmonic estimation for harmonic observability. Simulations and comparisons are provided to illustrate the performance of the proposed method against that obtained using a Kalman filter and fast Fourier transform (FFT). A number of scenarios such as measurement noise and change in amplitude of harmonic injections are simulated to verify the accuracy of the proposed approach and the results are included
The relationship between polycyclic aromatic hydrocarbon emission and far-infrared dust emission from NGC 2403 and M83
No full textWho does what research? KfWf survey of UK vegetation fire researchers
No full textWildfire costs UK Fire Services alone £55 million pa. Wildfire management is a truly cross-disciplinary issue, affecting a wide array of stakeholders operating in different scales from the Cabinet Office Civil Contingencies Secretariat, Department for Communities and Local Government (the Government lead for wildfire), DEFRA agencies (Forestry Commission, Natural England, Met Office), Fire Services, Ministry of Defence, Network Rail, Highways Agency, Association of National Park Authorities, Heather Trust, Confederation of Forest industries, landowners, to land-managers. The majority of which also constitutes the England and Wales Wildfire Forum (EWWF), the key, wide-ranging, public-private stakeholder group for wildfire. Up until now stakeholders of the EWWF used to contact a select few individuals for consultation and advice over wildfire and vegetation fire issues in the UK. This NERC IAA-funded project aims to develop a ‘who does what’ database focusing on UK-based researchers with interest and relevant research across the nation. In giving added visibility to NERC-produced research, it will facilitate knowledge exchange between researchers and stakeholders. The database will be a first-base hub where researchers working on vegetation fire will be able to make their work more widely available and potentially increase its impact. It should also help researchers develop their peer-to-peer network