Elasticity solutions for a transversely isotropic functionally graded circular plate subject to an axisymmetric transverse load qrk

AbstractThis paper considers the bending of transversely isotropic circular plates with elastic compliance coefficients being arbitrary functions of the thickness coordinate, subject to a transverse load in the form of qrk (k is zero or a finite even number). The differential equations satisfied by stress functions for the particular problem are derived. An elaborate analysis procedure is then presented to derive these stress functions, from which the analytical expressions for the axial force, bending moment and displacements are obtained through integration. The method is then applied to the problem of transversely isotropic functionally graded circular plate subject to a uniform load, illustrating the procedure to determine the integral constants from the boundary conditions. Analytical elasticity solutions are presented for simply-supported and clamped plates, and, when degenerated, they coincide with the available solutions for an isotropic homogenous plate. Two numerical examples are finally presented to show the effect of material inhomogeneity on the elastic field in FGM plates

Process variation in Laser Powder Bed Fusion of Ti-6Al-4V

In this work, a concept of using surface roughness data as an evaluation tool of the process variation in a commercial Laser Powder Bed Fusion (L-PBF) machine is demonstrated. The interactive effects of powder recoating, spatter generation, gas flow and heat transfer are responsible for the intra-build quality inconsistency of the L-PBF process. Novel specimens and experiments were designed to investigate how surface roughness varies across the build volume and with the progression of a build. The variation in roughness has a clear and repeatable pattern due to the strong impact of the orientation of inclined surface to the laser origin. The effects of other factors such as exposure sequence of specimens, build height, and recoating process are less prominent and are difficult to isolate. A neural network regression model was built upon the large dataset in measured Ra values. The neural network model was applied to predict distribution of roughness within the build volume under hypothetical processing conditions. Connections between the predicted variation in roughness and underlying physical mechanisms are discussed. The present work has value for machine qualification and modifications which lead to the manufacturing of parts with better consistency in quality. The detailed variation observed in surface roughness can be used as a reference for designing experiments to optimise processing parameters in order to minimise the roughness of inclined surfaces

JAK2V617F promotes replication fork stalling with disease-restricted impairment of the intra-S checkpoint response

Cancers result from the accumulation of genetic lesions, but the cellular consequences of driver mutations remain unclear, especially during the earliest stages of malignancy. The V617F mutation in the JAK2 non-receptor tyrosine kinase (JAK2V617F) is present as an early somatic event in most patients with myeloproliferative neoplasms (MPNs), and the study of these chronic myeloid malignancies provides an experimentally tractable approach to understanding early tumorigenesis. Introduction of exogenous JAK2V617F impairs replication fork progression and is associated with activation of the intra-S checkpoint, with both effects mediated by phosphatidylinositide 3-kinase (PI3K) signaling. Analysis of clonally derived JAK2V617F-positive erythroblasts from MPN patients also demonstrated impaired replication fork progression accompanied by increased levels of replication protein A (RPA)-containing foci. However, the associated intra-S checkpoint response was impaired in erythroblasts from polycythemia vera (PV) patients, but not in those from essential thrombocythemia (ET) patients. Moreover, inhibition of p53 in PV erythroblasts resulted in more gamma-H2Ax (γ-H2Ax)–marked double-stranded breaks compared with in like-treated ET erythroblasts, suggesting the defective intra-S checkpoint function seen in PV increases DNA damage in the context of attenuated p53 signaling. These results demonstrate oncogene-induced impairment of replication fork progression in primary cells from MPN patients, reveal unexpected disease-restricted differences in activation of the intra-S checkpoint, and have potential implications for the clonal evolution of malignancies

THE THERMO-HYDRODYNAMICS OF A CONCENTRIC OHMIC HEATER FOR PROCESSING DAIRY FLUIDS

The thermo-hydraulic performance of a 300W concentric annular ohmic heater was investigated. To minimize possible electrochemical reactions and corrosion, a higher frequency was applied and factors of field strength and frequency were studied. 2D computer simulation solving momentum, thermal and electrical energy was performed using the FlexPDE software. A good agreement between experimental and analytical analysis of static heating was obtained. There were significant differences between calculated and measured wall temperature near the entrance. The calculated outlet temperature was however in reasonable agreement with the experiment value

Sensitivity limitations in optical speed meter topology of gravitational-wave antennae

The possible design of QND gravitational-wave detector based on speed meter principle is considered with respect to optical losses. The detailed analysis of speed meter interferometer is performed and the ultimate sensitivity that can be achieved is calculated. It is shown that unlike the position meter signal-recycling can hardly be implemented in speed meter topology to replace the arm cavities as it is done in signal-recycled detectors, such as GEO 600. It is also shown that speed meter can beat the Standard Quantum Limit (SQL) by the factor of $\sim 3$ in relatively wide frequency band, and by the factor of $\sim 10$ in narrow band. For wide band detection speed meter requires quite reasonable amount of circulating power $\sim 1$ MW. The advantage of the considered scheme is that it can be implemented with minimal changes in the current optical layout of LIGO interferometer.Comment: 20 pages, 12 figure

Magnetic resonance imaging of glutamate in neuroinflammation

AbstractInflammation in central nervous system (CNS) is one of the most severe diseases, and also plays an impellent role in some neurodegenerative diseases. Glutamate (Glu) has been considered relevant to the pathogenesis of neuroinflammation. In order to diagnose neuroinflammation incipiently and precisely, we review the pathobiological events in the early stages of neuroinflammation, the interactions between Glu and neuroinflammation, and two kinds of magnetic resonance techniques of imaging Glu (chemical exchange saturation transfer and magnetic resonance spectroscopy)

Numerical renormalization group study of the 1D t-J model

The one-dimensional (1D) $t-J$ model is investigated using the density matrix renormalization group (DMRG) method. We report for the first time a generalization of the DMRG method to the case of arbitrary band filling and prove a theorem with respect to the reduced density matrix that accelerates the numerical computation. Lastly, using the extended DMRG method, we present the ground state electron momentum distribution, spin and charge correlation functions. The $3k_F$ anomaly of the momentum distribution function first discussed by Ogata and Shiba is shown to disappear as $J$ increases. We also argue that there exists a density-independent $J_c$ beyond which the system becomes an electron solid.Comment: Wrong set of figures were put in the orginal submissio

Short-time dynamics and magnetic critical behavior of two-dimensional random-bond Potts model

The critical behavior in the short-time dynamics for the random-bond Potts ferromagnet in two-dimensions is investigated by short-time dynamic Monte Carlo simulations. The numerical calculations show that this dynamic approach can be applied efficiently to study the scaling characteristic, which is used to estimate the critical exponents theta, beta/nu and z for the quenched disorered systems from the power-law behavior of the kth moments of magnetizations.Comment: 10 pages, 4 figures Soft Condensed Matte

Topological order in 1D Cluster state protected by symmetry

We demonstrate how to construct the Z2*Z2 global symmetry which protects the ground state degeneracy of cluster states for open boundary conditions. Such a degeneracy ultimately arises because the set of stabilizers do not span a complete set of integrals of motion of the cluster state Hamiltonian for open boundary conditions. By applying control phase transformations, our construction makes the stabilizers into the Pauli operators spanning the qubit Hilbert space from which the degeneracy comes.Comment: 1 figure, To be published in Quantum Information Processin

Triple-quark elastic scatterings and thermalization

Triple-quark elastic scattering amplitudes from perturbative QCD are first calculated and then used in a transport equation to study the thermalization of quark matter. By examining momentum isotropy to which the transport equation leads, we can determine thermalization time and offer an initial thermal quark distribution function. With an anisotropic initial quark distribution, which is relevant to quark matter initially created in a central Au-Au collision at \sqrt {s_{NN}}=200 GeV, the transport equation gives a time of the order of 1.8 fm/c for quark matter itself to thermalize by the triple-quark scatterings.Comment: 19 pages, 4 figures, 1 table, LaTex, define u12,u13,u21,u23,u31,u3