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Engineering fatigue is a very prevalent and dangerous phenomenon that limits the useful life span of mechanical structures. It can be found in most engineered structures and machinery that are made from metallic or composite materials. The life prediction methodology under variable amplitude loading (VAL), however, has not reached maturity due to the complexity of the loading. This complexity results in load sequence effects, which significantly alter the fatigue life. Since most of the realistic loading experienced by engineered structures is of variable amplitude nature, and the corresponding responses at the defect site are highly irregular, characterization of the VAL and its resulting damage is paramount. Fatigue life estimation under VAL conventionally uses methods based on the Miner's Rule or the cumulative damage rule (CDR) in conjunction with the rainflow counting method. However, CDR does not account for the load interaction/sequence effects induced by local residual stress (or crack opening stress) variations., Comment: 24 Pages

We study the energy transfer process in quantum battery systems consisting of multiple central spins and bath spins. Here with "quantum battery" we refer to the central spins, whereas the bath serves as the "charger". For the single central-spin battery, we analytically derive the time evolutions of the energy transfer and the charging power with arbitrary number of bath spins. For the case of multiple central spins in the battery, we find the scaling-law relation between the maximum power $P_{max}$ and the number of central spins $N_B$. It approximately satisfies a scaling law relation $P_{max}\propto N_{B}^{\alpha}$, where scaling exponent $\alpha$ varies with the bath spin number $N$ from the lower bound $\alpha =1/2$ to the upper bound $\alpha =3/2$. The lower and upper bounds correspond to the limits $N\to 1$ and $N\gg N_B$, respectively. In thermodynamic limit, by applying the Holstein-Primakoff (H-P) transformation, we rigorously prove that the upper bound is $P_{max}=0.72 B A \sqrt{N} N_{B}^{3/2}$, which shows the same advantage in scaling of a recent charging protocol based on the Tavis-Cummins model. Here $B$ and $A $ are the external magnetic field and coupling constant between the battery and the charger., Comment: 10 pages + 5 figures

We propose a generalization of the coherent anomaly method to extract the critical exponents of a phase transition occurring in the steady-state of an open quantum many-body system. The method, originally developed by Suzuki [J. Phys. Soc. Jpn. {\bf 55}, 4205 (1986)] for equilibrium systems, is based on the scaling properties of the singularity in the response functions determined through cluster mean-field calculations. We apply this method to the dissipative transverse-field Ising model and the dissipative XYZ model in two dimensions obtaining convergent results already with small clusters., Comment: Accepted version, 9 pages, 7 figures

The industrial life cycle theory has proved to be helpful for describing the evolution of industries from birth to maturity. This paper is to highlight the historical evolution stage of Atlantic City's gambling industry in a structural framework covered by industrial market, industrial organization, industrial policies and innovation. Data mining was employed to obtain from local official documents, to verify the module of industrial life cycle in differential phases as introduction, development, maturity and decline. The trajectory of Atlantic City's gambling sector evolution reveals the process from the stages of introduction to decline via a set of variables describing structural properties of this industry such as product, market and organization of industry under a special industry environment in which industry recession as a result of theory of industry life cycle is a particular evidence be proved again. Innovation of the gambling industry presents the ongoing recovering process of the Atlantic City gambling industry enriches the theory of industrial life cycle in service sectors., Comment: 15 pages, 3 figures, 1 table

Recently, multifold fermions characterized by band crossings with multifold degeneracy and Fermi surfaces with nontrivial Chern numbers have been discovered experimentally in AlPt[arXiv:1812.03310] and XSi(X=Rh,Co)[arXiv:1812.04466][arXiv:1901.03358][arXiv:1809.01312]. In this work, we largely expand the family of multifold fermion materials by pointing out that several well-studied noncentrosymmetric superconductors are indeed multifold fermion metals. Importantly, their normal state topological properties, which have been ignored in previous studies, play an important role in the superconducting properties. Taking Li$_2$Pd$_3$B and Li$_2$Pt$_3$B as examples, we found a large number of unconventional degenerate points, such as double spin-1, spin-3/2, Weyl and double Weyl topological band crossing points near the Fermi energy, which result in finite Chern numbers on Fermi surfaces. Long Fermi arc states in Li$_2$Pd$_3$B, originating from the nontrivial band topology were found. Importantly, it has been shown experimentally that Li$_2$Pd$_3$B and Li$_2$Pt$_3$B are fully gapped and gapless superconductors, respectively. By analyzing the possible pairing symmetries, we suggest that Li$_2$Pd$_3$B can be a DIII class topological superconductor with Majorana surface states, even though the spin-orbit coupling in Li$_2$Pd$_3$B is negligible. Interestingly, Li$_2$Pt$_3$B, being gapless, is likely to be a nodal topological superconductor with dispersionless surface Majorana modes. We further identified that several noncentrosymmetric superconductors, such as Mo$_3$Al$_2$C, PdBiSe, Y$_2$C$_3$ and La$_2$C$_3$, are multifold fermion superconductors whose normal state topological properties have been ignored in previous experimental and theoretical studies.

Superconducting magnetoelectric effect, which is the current-induced magnetization in a superconductor, mainly focused on the spin magnetization in previous studies, but ignore the effect of the orbital magnetic moments carried by the paired Bloch electrons. In this work, we show that orbital magnetic moments in superconductors can induce large orbital magnetization in the presence of a current. We constructed a unified description for the current-induced spin and orbital magnetization across the superconductivity normal metal phase transition. We find that in a superconductor with uniform pairing, the current-induced magnetization at a given current density is the same as that in its normal metal state, while with the nonuniform superconducting pairing, the current-induced magnetization exhibits an abrupt change in magnitude near the superconductivity normal metal phase transition. Importantly, our theory predicts the orbital magnetoelectric effect in superconducting twisted bilayer graphene which has paired Bloch electrons with large orbital magnetic moments and negligible spin-orbit coupling. We propose that the measurement of the current-induced orbital magnetoelectric effect can be used to detect the possible nonuniform pairings in twisted bilayer graphene and other newly discovered superconductors with non-trivial Berry curvatures., Comment: 5 pages, 3 figures, plus supplementary material. Comments are welcome

We develop an optimization approach to model the magnetic field configuration of magnetic clouds, based on a linear-force free formulation in three dimensions. Such a solution, dubbed the Freidberg solution, is kin to the axi-symmetric Lundquist solution, but with more general "helical symmetry". The merit of our approach is demonstrated via its application to two case studies of in-situ measured magnetic clouds. Both yield results of reduced $\chi^2\approx 1$. Case 1 shows a winding flux rope configuration with one major polarity. Case 2 exhibits a double-helix configuration with two flux bundles winding around each other and rooted on regions of mixed polarities. This study demonstrates the three-dimensional complexity of the magnetic cloud structures., Comment: Submitted to ApJL on Aug 24, 2020; rejected by Editor without review... Resubmitted to GRL, in press (see DOI; Open Access)

The local intrinsic parallel current density driven by electron drift wave (DW) turbulence including electromagnetic (EM) effects is analytically studied. The scalings of the ratios of intrinsic current density driven by residual turbulent flux and by turbulent source to the bootstrap current density with electron density and temperature are predicted to be $T_e^{3/4}T_i/n_e$ and $T_eT_i/n_e$, respectively. Based on the typical parameters in DIII-D pedestal region, the local intrinsic current density driven by both the residual turbulent flux and the turbulent source is negligible. However, despite the negligible turbulent source driven current, the residual turbulent flux driven local intrinsic current density by EM DW turbulence can reach about 66% of the bootstrap current density for ITER pedestal parameters due to much lower collisionality in ITER than in DIII-D. Moreover, the contributions from adiabatic ES parts, non-adiabatic ES parts and non-adiabatic EM parts of the plasma response to electromagnetic fluctuations are analyzed. It is found that there exists strong cancelation between non-adiabatic ES response and the non-adiabatic EM response for the ITER pedestal case, and thus the kinetic stress contributed by the adiabatic ES response of parallel electron pressure dominates the intrinsic current drive. This is different from the ES electron DW case. Therefore, the EM effects on turbulence driven intrinsic current density should be carefully considered in the future reactor with high ratio of electron pressure to the magnetic pressure and steep pressure profile.

The mean parallel current density evolution equation is presented using electromagnetic (EM) gyrokinetic equation. There exist two types of intrinsic current driving mechanisms resulted from EM electron temperature gradient (ETG) turbulence. The first type is the divergence of residual turbulent flux including a residual stress-like term and a kinetic stress-like term. The second type is named as residual turbulent source, which is driven by the correlation between density and parallel electric field fluctuations. The intrinsic current density driven by the residual turbulent source is negligible as compared to that driven by the residual turbulent flux. The ratio of intrinsic current density driven by EM ETG turbulence to the background bootstrap current density is estimated. The local intrinsic current density driven by the residual turbulent flux for mesoscale variation of turbulent flux can reach about 80% of the bootstrap current density in the core region of ITER standard scenario, but there is no net intrinsic current on a global scale. Based on this, the local intrinsic current driven by EM micro-turbulence and its effects on local modification of the profile of safety factor may be needed to be carefully taken into account in the future device with high beta_e which is the ratio between electron pressure to the magnetic pressure.