Claas Bierwisch, Hanna Lagger, Michael Moseler

We present the development of smoothed particle hydrodynamics (SPH) simulations for the investigation of the industrial application of abrasive flow machining (AFM). This process cannot be observed in-situ in experiments and therefore demands for numerical simulations at a grain-size process scale. There are only a few numerical models available for the AFM process, which are strongly simplified. In order to optimize the machining, an explicit approach of including individual grains in the abrasive suspension is essential. These grains are simulated by individual clusters of SPH particles, which are integrated in time by a rigid body solver. For the correct force transmission between the suspended abrasive particle and the workpiece, a realistic representation of the stress in the fluid model of the suspension is necessary. Therefore, the rheology of the fluids, containing the abrasive grains, has been experimentally characterized. Since the tested suspensions show a viscoelastic behavior, we have employed a viscoelastic fluid model and have used experimentally gathered data for the calibration of the applied numerical model. The abrasive process on a workpiece and the removal of material from its surface is modeled by the Johnson-Cook ductile flow stress model in combination with a strain-based failure criterion. We show that the particle method can reproduce key aspects for the simulation of the process of abrasive flow machining. By the application of the Johnson-Cook model, we are able to determine wear contacts between solid materials on a microscopic scale.

Markus Roth, Jason Jackiewicz, Shukur Kholikov

The solar meridional flow is a crucial ingredient in modern dynamo theory. Seismic estimates of this flow have, however, been contradictory in deeper layers below about $0.9\,R_\odot$. Results from time-distance helioseismology have so far been obtained using the ray approximation. Here, we perform inversions using the Born approximation. The initial result is similar to the result previously obtained by Jackiewicz et al. (2015) using ray kernels while using the same set of GONG data and the SOLA inversion technique. However, we show that the assumption of uncorrelated measurements used in earlier studies may lead to inversion errors being underestimated by a factor of about two to four. In a second step, refined inversions are performed using the full covariance matrix and a regularization for cross-talk. As the results are found to depend on the threshold used in the singular value decomposition, they were obtained for a medium threshold ($10^{−7} − 10^{−5}$, about 50% of the values used) and a threshold lower by a factor of 10 (about 70% of the values used). The result obtained with the medium threshold is again similar to the original, with less latitudinal variation. However, using the lower threshold, the inverted flow in the southern hemisphere shows two or three cells stacked radially depending on the associated radial flows. Both the single-cell and the multi-cell profiles are consistent with the measured travel times. All our results confirm a shallow return flow at about $0.9\,R_\odot$.

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Markus Roth, Jason Jackiewicz, and Shukur Kholikov

Accurate measurements of deep solar meridional flow are of vital interest for understanding the solar dynamo. In this paper, we validate a recently developed method for obtaining sensitivity functions (kernels) for travel-time measurements to solar interior flows using the Born approximation in spherical geometry, which is expected to be more accurate than the classical ray approximation. Furthermore, we develop a numerical approach to efficiently compute a large number of kernels based on the separability of the eigenfunctions into their horizontal and radial dependence. The validation is performed using a hydrodynamic simulation of linear wave propagation in the Sun, which includes a standard single-cell meridional flow profile. We show that, using the Born approximation, it is possible to accurately model observational quantities relevant for time–distance helioseismology such as the mean power spectrum, disk-averaged cross-covariance functions, and travel times in the presence of a flow field. In order to closely match the model to observations, we show that it is beneficial to use mode frequencies and damping rates that were extracted from the measured power spectrum. Furthermore, the contribution of the radial flow to the total travel time is found to reach 20% of the contribution of the horizontal flow at travel distances over 40°. Using the Born kernels and a 2D SOLA inversion of travel times, we can recover most features of the input meridional flow profile. The Born approximation is thus a promising method for inferring large-scale solar interior flows.

Markus Roth, Wolfgang Zima, Aaron C. Birch, Laurent Gizon

We extend an existing Born approximation method for calculating the linear sensitivity of helioseismic travel times to flows from Cartesian to spherical geometry. This development is necessary for using the Born approximation for inferring large-scale flows in the deep solar interior. In a first sanity check, we compare two f−mode kernels from our spherical method and from an existing Cartesian method. The horizontal and total integrals agree to within 0.3 %. As a second consistency test, we consider a uniformly rotating Sun and a travel distance of 42 degrees. The analytical travel-time difference agrees with the forward-modelled travel-time difference to within 2 %. In addition, we evaluate the impact of different choices of filter functions on the kernels for a meridional travel distance of 42 degrees. For all filters, the sensitivity is found to be distributed over a large fraction of the convection zone. We show that the kernels depend on the filter function employed in the data analysis process. If modes of higher harmonic degree (90≲l≲170) are permitted, a noisy pattern of a spatial scale corresponding to l≈260 appears near the surface. When mainly low-degree modes are used (l≲70), the sensitivity is concentrated in the deepest regions and it visually resembles a ray-path-like structure. Among the different low-degree filters used, we find the kernel for phase-speed filtered measurements to be best localized in depth.

Yuxue Cai, Jan Michels, Julien Bachmann, Christian Klinke

We demonstrate that by means of a local top-gate current oscillations can be observed in extended, monolayered films assembled from monodisperse metal nanocrystals - realizing transistor function. The oscillations in this metal-based system are due to the occurrence of a Coulomb energy gap in the nanocrystals which is tunable via the nanocrystal size. The nanocrystal assembly by the Langmuir-Blodgett method yields homogeneous monolayered films over vast areas. The dielectric oxide layer protects the metal nanocrystal field-effect transistors from oxidation and leads to stable function for months. The transistor function can be reached due to the high monodispersity of the nanocrystals and the high super-crystallinity of the assembled films. Due to the fact that the film consists of only one monolayer of nanocrystals and all nanocrystals are simultaneously in the state of Coulomb blockade the energy levels can be influenced efficiently (limited screening). Ref: J. Appl. Phys. 114 (2013) 034311.

Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Michael Peter Ellis, James Jeffery Peoples, James Joseph Meuer, Johanne Dodon, John Lawrence Griffin, John Suzuki, Joseph Michael Foty, Judy Weber, Julia Grace McCammon, Karen Brynes Allen, Kathryn Regina Sweas, Lezley Jo-Anne Wright, Lisa A. Knoll, Madeline E. Michaels, Margaret Kweya Wahl, Mark E. Stutheit, Michelle Barnard, Muriel Mae Ranger, Paromvong Sinbandhit

With the increasing popularity of herbomineral preparations in healthcare, a new proprietary herbomineral formulation was formulated with ashwagandha root extract and minerals viz. zinc, magnesium, and selenium. The aim of the study was to evaluate the immunomodulatory potential of Biofield Energy Healing (The Trivedi Effect®) on the herbomineral test formulation using mice splenocytes. The test formulation was divided into two parts. One part was the control without the Biofield Treatment. The other part was labelled the Biofield Treated sample, which received the Biofield Energy Healing Treatment remotely from twenty renowned Biofield Energy Healers. The splenocyte cells were exposed with the test formulation at ranges of 0.00001053 to 10.53 µg/mL for cell viability by MTT assay, with cell viability ranging from 77.50% to 176.52%. TNF-α was significantly inhibited by 15.88%, 15.28%, 12.30%, 12.60%, and 22.72% at 0.00001053, 0.001053, 0.1053, 1.053, and 10.53 µg/mL, respectively in the Biofield Treated test formulation compared to the vehicle control (VC). TNF-α was significantly reduced by 2.33% and 8.35% at 1.053 and 10.53 µg/mL, respectively compared to the untreated test formulation. IL-1β was significantly reduced by 30.81%, 27.36%, 23.92%, 18.40%, 11.27%, and 21.16% at 0.00001053, 0.0001053, 0.001053, 0.01053, 0.1053, and 1.053 µg/mL, respectively in the Biofield Treated test formulation compared to the VC. IL-1β was significantly reduced by 48.63% (p≤0.001) and 15.28% at 0.00001053 and 0.0001053 µg/mL, respectively in the Biofield Treated test formulation compared to the untreated test formulation. MIP-1α expression was inhibited by the Biofield Treated test formulation and showed immunosuppressive activity at 0.01053, 0.1053, 1.053, and 10.53 µg/mL by 22.33%, 16.25%, 15.58%, and 21.83%, respectively compared to the VC. The Biofield Treated test formulation significantly reduced the MIP-1α expression by 13.27% and 15.67% (p<0.05) at 0.01053 and 10.53 µg/mL, respectively compared to the untreated test formulation. The results showed the expression of IFN-γ was significantly reduced by 33.45%, 25.38%, 37.15%, 27.74%, 32.44%, 23.03%, and 44.21% at 0.00001053, 0.0001053, 0.001053, 0.01053, 0.1053, 1.053, and 10.53 µg/mL, respectively in the Biofield Treated test formulation compared to the VC. Further, the IFN-γ level was significantly decreased by 19.02% at 10.53 µg/mL in the Biofield Treated test formulation compared to the untreated test formulation. Overall, the results demonstrate that The Trivedi Effect® Biofield Energy Healing (TEBEH) significantly enhanced the anti-inflammatory and immunomodulatory properties of the treated formulation, and may also be useful in organ transplants, anti-aging, and stress management by improving overall health and quality of life.