Thermal barrier coating life prediction model development

The objective is to develop an integrated life prediction model accounting for all potential life-limiting thermal barrier coating (TBC) degradation and failure modes, including spallation resulting from cyclic thermal stress, oxidation degradation, hot corrosion, erosion and foreign object damage

Thermal barrier coating life prediction model development

A methodology was established to predict thermal barrier coating life in an environment simulative of that experienced by gas turbine airfoils. Specifically, work is being conducted to determine failure modes of thermal barrier coatings in the aircraft engine environment. Analytical studies coupled with appropriate physical and mechanical property determinations are being employed to derive coating life prediction model(s) on the important failure mode(s). An initial review of experimental and flight service components indicates that the predominant mode of TBC failure involves thermomechanical spallation of the ceramic coating layer. This ceramic spallation involves the formation of a dominant crack in the ceramic coating parallel to and closely adjacent to the metal-ceramic interface. Initial results from a laboratory test program designed to study the influence of various driving forces such as temperature, thermal cycle frequency, environment, and coating thickness, on ceramic coating spalling life suggest that bond coat oxidation damage at the metal-ceramic interface contributes significantly to thermomechanical cracking in the ceramic layer. Low cycle rate furnace testing in air and in argon clearly shows a dramatic increase of spalling life in the non-oxidizing environments

Convergence of nonlocal threshold dynamics approximations to front propagation

In this note we prove that appropriately scaled threshold dynamics-type algorithms corresponding to the fractional Laplacian of order $\alpha \in (0,2)$ converge to moving fronts. When $\alpha \geqq 1$ the resulting interface moves by weighted mean curvature, while for $\alpha <1$ the normal velocity is nonlocal of ``fractional-type.'' The results easily extend to general nonlocal anisotropic threshold dynamics schemes.Comment: 19 page

Non-equilibrium phase transitions in one-dimensional kinetic Ising models

A family of nonequilibrium kinetic Ising models, introduced earlier, evolving under the competing effect of spin flips at {\it zero temperature} and nearest neighbour random spin exchanges is further investigated here. By increasing the range of spin exchanges and/or their strength the nature of the phase transition 'Ising-to-active' becomes of (dynamic) mean-field type and a first order tricitical point is located at the Glauber ($\delta=0$) limit. Corrections to mean-field theory are evaluated up to sixth order in a cluster approximation and found to give good results concerning the phase boundary and the critical exponent $\beta$ of the order parameter which is obtained as $\beta\simeq1.0$.Comment: 15 pages, revtex file, figures available at request from [email protected] in postscript format, submitted to J.Phys.

Calibration of the Particle Density in Cellular-Automaton Models for Traffic Flow

We introduce density dependence of the cell size in cellular-automaton models for traffic flow, which allows a more precise correspondence between real-world phenomena and what observed in simulation. Also, we give an explicit calibration of the particle density particularly for the asymmetric simple exclusion process with some update rules. We thus find that the present method is valid in that it reproduces a realistic flow-density diagram.Comment: 2 pages, 2 figure

Band structure of ZnO from resonant x-ray emission spectroscopy

Soft x-ray emission and absorption spectroscopy of the O K-edge are employed to investigate the electronic structure of wurtzite ZnO(0001). A quasiparticle band structure calculated within the GW approximation agrees well with the data, most notably with the energetic location of the Zn3d - O2p hybridized state and the anisotropy of the absorption spectra. Dispersion in the band structure is mapped using the coherent k-selective part of the resonant x-ray emission spectra. We show that a more extensive mapping of the bands is possible in the case of crystalline anisotropy such as that found in ZnO.Comment: 5 pages, 5 figure

What are the resourcing requirements for an Aboriginal and Torres Strait Islander primary healthcare research project?

Objective and importance To explore the role of resourcing during an Aboriginal and Torres Strait Islander primary healthcare research project. Study type Process evaluation using grounded theory approaches of a national Aboriginal and Torres Strait Islander research project (N=500) named Getting it Right: The validation study. Methods Qualitative semi-structured interviews with thirty-six primary healthcare staff and four community members from nine of ten primary healthcare services (participating services) involved in the research project. Interviews included questions about the resources needed to conduct the research project, including flexible reimbursement to participating services (allocated within services), human resources and reimbursement to research participants (vouchers). Qualitative data were triangulated with participant feedback (questions about the aPHQ-9 [depression screening tool under examination] and free-text feedback collected during the research project), study administrative data (budgets, contracts, communication logs and ethics correspondence) and field notes kept by the interviewer. Results Three themes were identified: 1) the influence of reimbursement on participating services and the research project: 2) the influence of human resources on the research project at participating services; and 3) the consequences of offering vouchers to reimburse research participants. Reimbursement was allocated to research expenses (human resources and logistics) or non-research expenses (service operations, equipment and conference attendance costs). Most services opted to offer vouchers to compensate participants for their time, which staff considered was appropriate recognition of participants’ contributions and facilitated recruitment. Some staff described some potential unintended negative consequences from vouchers, including creating a welfare mentality or the wrong precedent. Conclusion Primary healthcare research should have sufficient resourcing available, including human resource capacity, to achieve research targets. Research planning should include consideration of the existing commitments, priorities and human capacity needs of services and patients

Non equilibrium steady states: fluctuations and large deviations of the density and of the current

These lecture notes give a short review of methods such as the matrix ansatz, the additivity principle or the macroscopic fluctuation theory, developed recently in the theory of non-equilibrium phenomena. They show how these methods allow to calculate the fluctuations and large deviations of the density and of the current in non-equilibrium steady states of systems like exclusion processes. The properties of these fluctuations and large deviation functions in non-equilibrium steady states (for example non-Gaussian fluctuations of density or non-convexity of the large deviation function which generalizes the notion of free energy) are compared with those of systems at equilibrium.Comment: 35 pages, 9 figure

Gene and protein expression of glucose transporter 1 and glucose transporter 3 in human laryngeal cancer—the relationship with regulatory hypoxia-inducible factor-1α expression, tumor invasiveness, and patient prognosis

Increased glucose uptake mediated by glucose transporters and reliance on glycolysis are common features of malignant cells. Hypoxia-inducible factor-1α supports the adaptation of hypoxic cells by inducing genes related to glucose metabolism. The contribution of glucose transporter (GLUT) and hypoxia-inducible factor-1α (HIF-1α) activity to tumor behavior and their prognostic value in head and neck cancers remains unclear. The aim of this study was to examine the predictive value of GLUT1, GLUT3, and HIF-1α messenger RNA (mRNA)/protein expression as markers of tumor aggressiveness and prognosis in laryngeal cancer. The level of hypoxia/metabolic marker genes was determined in 106 squamous cell laryngeal cancer (SCC) and 73 noncancerous matched mucosa (NCM) controls using quantitative realtime PCR. The related protein levels were analyzed by Western blot. Positive expression of SLC2A1, SLC2A3, and HIF-1α genes was noted in 83.9, 82.1, and 71.7 % of SCC specimens and in 34.4, 59.4, and 62.5 % of laryngeal cancer samples. Higher levels of mRNA/protein for GLUT1 and HIF-1α were noted in SCC compared to NCM (p<0.05). SLC2A1 was found to have a positive relationship with grade, tumor front grading (TFG) score, and depth and mode of invasion (p<0.05). SLC2A3 was related to grade and invasion type (p<0.05). There were also relationships of HIF-1α with pTNM, TFG scale, invasion depth and mode, tumor recurrences, and overall survival (p<0.05). In addition, more advanced tumors were found to be more likely to demonstrate positive expression of these proteins. In conclusion, the hypoxia/metabolic markers studied could be used as molecular markers of tumor invasiveness in laryngeal cancer.This work was supported, in part, by the statutory fund of the Department of Cytobiochemistry, University of Łódź, Poland (506/811), and by grant fromtheNational Science Council, Poland (N403 043 32/2326)

Patient-reported outcomes for tofacitinib with and without methotrexate, or adalimumab with methotrexate, in rheumatoid arthritis: A phase IIIB/IV trial

© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Objective To provide the first direct comparison of patient-reported outcomes (PROs) following treatment with tofacitinib monotherapy versus tofacitinib or adalimumab (ADA) in combination with methotrexate (MTX) in patients with rheumatoid arthritis (RA) with inadequate response to MTX (MTX-IR). Methods ORAL Strategy (NCT02187055), a phase IIIB/IV, head-to-head, randomised controlled trial, assessed non-inferiority between tofacitinib 5 mg two times per day monotherapy, tofacitinib 5 mg two times per day+MTX and ADA 40 mg every other week+MTX. PROs assessed included the following: Patient Global Assessment of disease activity (PtGA), Pain, Health Assessment Questionnaire-Disability Index, Functional Assessment of Chronic Illness Therapy-Fatigue and 36-Item Short-Form Health Survey (SF-36) summary and domain scores. Results Substantial improvements from baseline were reported across all PROs in all treatment arms, which, in the majority, met or exceeded minimum clinically important differences. Compared with tofacitinib monotherapy, tofacitinib+MTX combination treatment conferred significantly greater improvements in PtGA, Pain and SF-36 physical component summary scores at month 6. Statistically or numerically greater improvements were often, but not uniformly, reported for combination treatments compared with tofacitinib monotherapy at other time points. Conclusion Treatment with tofacitinib+MTX, ADA+MTX and tofacitinib monotherapy resulted in clinically meaningful improvements in PROs in MTX-IR patients with RA. These were comparatively greater with combination treatments versus tofacitinib monotherapy, although differences between treatment arms were small, limiting our ability to confer clinical meaning. Trial registration number NCT02187055