The effect of linear guide representation for topology optimization on a five-axis milling machine

Topology optimization is a countermeasure to obtain lightweight and stiff structures for machine tools. Topology optimizations are applied at component level due to computational limitations, therefore linear guides’ rolling elements are underestimated in most of the cases. Stiffness of the entire assembly depends on the least stiff components which are identified as linear guides in the current literature. In this study, effects of linear guide’s representation in virtual environment are investigated at assembly level by focusing on topology optimization. Two different contact models are employed for rolling elements in the linear guides. Reliability of the contact models are verified with experiments. After the verification, heavy duty cutting conditions are considered for the system and topology optimization is performed for two different contact models to reduce the mass of the structure. The difference caused by the representation of rolling elements is demonstrated for the same topology algorithm and the optimization results are compared for the models. And then, the effect of using stiffer linear guides in the five-axis milling machine is investigated by increasing the stiffness of the contact elements. Afterwards, an extensive Multiple-Physics comparison for different linear guide’s representations is executed for dynamically and thermally by crossing the representations for the proposed structures. As first, dynamic behavior improvement and error percentage due to unrealistic representation is investigated, while thermal behavior is investigated as the second. As the last, it is demonstrated that minimum compliance problem contributes dynamic and thermal stiffness with realistic boundary conditions for multi-component level topology optimization applications

η\eta-Ricci solitons in (ε)(\varepsilon)-almost paracontact metric manifolds

The object of this paper is to study $\eta$-Ricci solitons on $(\varepsilon)$-almost paracontact metric manifolds. We investigate $\eta$-Ricci solitons in the case when its potential vector field is exactly the characteristic vector field $\xi$ of the $(\varepsilon)$-almost paracontact metric manifold and when the potential vector field is torse-forming. We also study Einstein-like and $(\varepsilon)$-para Sasakian manifolds admitting $\eta$-Ricci solitons. Finally we obtain some results for $\eta$-Ricci solitons on $(\varepsilon)$-almost paracontact metric manifolds with a special view towards parallel symmetric (0,2)-tensor fields.Comment: 20 page

THE EFFECT OF QUERCETIN AND QUERCETIN-3-D-XYLOSIDE ON BREAST CANCER PROLIFERATION AND MIGRATION

Background and Purpose: The aim of this study is to investigate the migration, wound healing, colony formation, and cytotoxic effects of Quercetin-3-D-xyloside (reynoutrin), a quercetin derivative, in breast cancer cells Methods: In the present study, CRL-4010, MCF7 and MDA-MB-231 cells were used to evaluate the cytotoxic, antiproliferative and migration effects of reynoutrin on breast cancer. The IC50 concentration (400 mu g/ml) of reynoutrin, quercetin and cisplatin in the cells was determined. For cytotoxicity assessments, varying concentrations of quercetin, reynoutrin and cisplatin were applied and incubated 24h and 48h. In addition, to examine effects of reynoutrin on migration, cells were seeded in 6-well plates and incubated for 24 hours. For the colony formation assay cells were seeded to 12-well plates at a concentration of 1000 cells/well and incubated overnight. Results: These results indicated that reynoutrin markedly inhibit the cell viability in breast cancer. Conclusion: We have demonstrated for the first time with the present study that reynoutrin suppressed the progression of breast cancer cell proliferation induction and may provide a potential therapeutic target for breast cancer treatment. However, these results should be further confirmed by future more comprehensive studies

Influence of the symmetry energy on the nuclear binding energies and the neutron drip line position

A clear connection can be established between properties of nuclear matter and finite-nuclei observables, such as the correlation between the slope of the symmetry energy and dipole polarizability, or between compressibility and the isoscalar monopole giant resonance excitation energy. Establishing a connection between realistic atomic nuclei and an idealized infinite nuclear matter leads to a better understanding of underlying physical mechanisms that govern nuclear dynamics. In this work, we aim to study the dependence of the binding energies and related quantities (e.g. location of drip lines, the total number of bound even-even nuclei) on the symmetry energy $S_2(\rho)$. The properties of finite nuclei are calculated by employing the relativistic Hartree-Bogoliubov (RHB) model, assuming even-even axial and reflection symmetric nuclei. Calculations are performed by employing two families of relativistic energy density functionals (EDFs), based on different effective Lagrangians, constrained to a specific symmetry energy at saturation density $J$ within the interval of $30$--$36$ MeV. Nuclear binding energies and related quantities of bound nuclei are calculated between $8 \leq Z \leq 104$ from the two-proton to the two-neutron drip line. As the neutron drip line is approached, the interactions with stiffer $J$ tend to predict more bound nuclei, resulting in a systematic shift of the two-neutron drip line towards more neutron-rich nuclei. Consequentially, a correlation between the number of bound nuclei $N_{nucl}$ and $S_2(\rho)$ is established for a set of functionals constrained using the similar optimization procedures. The direction of the relationship between the number of bound nuclei and symmetry energy highly depends on the density under consideration.Comment: 9 pages, 5 figure

Global properties of nuclei at finite-temperature within the covariant energy density functional theory

In stellar environments nuclei appear at finite temperatures, becoming extremely hot in core-collapse supernovae and neutron star mergers. However, due to theoretical and computational complexity, most model calculations of nuclear properties are performed at zero temperature, while those existing at finite temperatures are limited only to selected regions of the nuclide chart. In this study we perform the global calculation of nuclear properties for even-even $8 \leq Z \leq 104$ nuclei at temperatures in range $0\le T \le 2$ MeV. Calculations are based on the finite temperature relativistic Hartree-Bogoliubov model supplemented by the Bonche-Levit-Vautherin vapor subtraction procedure. We find that near the neutron-drip line the continuum states have significant contribution already at moderate temperature $T\approx 1$ MeV, thus emphasising the necessity of the vapor subtraction procedure. Results include neutron emission lifetimes, quadrupole deformations, neutron skin thickness, proton and neutron pairing gaps, entropy and excitation energy. Up to the temperature $T\approx 1$ MeV nuclear landscape is influenced only moderately by the finite-temperature effects, mainly by reducing the pairing correlations. As the temperature increases further, the effects on nuclear structures become pronounced, reducing both the deformations and the shell effects.Comment: 18 pages, 14 figures, submitted to Physical Review