Setting the Quantum Integrand of M-Theory

Thermal barrier coatings (TBCs) have been investigated both experimentally and through simulation for mixing controlled combustion (MCC) concepts as a method for reducing heat transfer losses and increasing cycle efficiency, but it is still a very active research area. Early studies were inconclusive, with different groups discovering obstacles to realizing the theoretical potential. Nuanced papers have shown that coating material properties, thickness, microstructure, and surface morphology/roughness all can impact the efficacy of the thermal barrier coating and must be accounted for. Adding to the complexities, a strong spatial and temporal heat flux inhomogeneity exists for mixing controlled combustion (diesel) imposed onto the surfaces from the impinging flame jets. In support of the United States Department of Energy SuperTruck II program goal to achieve 55% brake thermal efficiency on a heavy-duty diesel engines, this study sought to develop a deeper insight into the inhomogeneous heat flux from mixing controlled combustion on thermal barrier coatings and to infer concrete guidance for designing coatings. To that end, a co-simulation approach was developed that couples high-fidelity computational fluid dynamics (CFD) modeling of in-cylinder processes and combustion, and finite element analysis (FEA) modeling of the thermal barrier-coated and metal engine components to resolve spatial and temporal thermal boundary conditions. The models interface at the surface of the combustion chamber; FEA modeling predicts the spatially resolved surface temperature profile, while CFD develops insights into the effect of the thermal barrier coating on the combustion process and the boundary conditions on the gas side. The paper demonstrates the capability of the framework to estimate cycle impacts of the temperature swing at the surface, as well as identify critical locations on the piston/thermal barrier coating that exhibit the highest charge temperature and highest heat fluxes. In addition, the FEA results include predictions of thermal stresses, thus enabling insight into factors affecting coating durability. An example of the capability of the framework is provided to illustrate its use for investigating novel coatings and provide deeper insights to guide future coating design.

Finite element analyses of multi-dimensional, partial differential equations require accurate and complete boundary condition assignments. However, continuous temporal and spatial values along physical boundaries are rarely available when solving realistic problems based on field data. To mitigate this situation a neural network system was developed and coupled with an interpolation routine. This innovative computational utility was used to provide continuous boundary condition information in time and space along physical boundaries of interest. The neural network was trained to predict the time response at discrete boundary locations based on field measurements at those locations. Once trained the neural network system was capable of providing a continuous time history for those locations. This system was then linked to an interpolation routine which handled the spatial component of the boundary condition specifications. These coupled routines facilitated rapid deployment and testing of various finite element representations. Further, the neural network system captured the transient physics of the situation more accurately than interpolation routines used previously.

Time-of-flight (TOF)-based two-phase upscaling for subsurface flow and transport

From Eq. (5.2.2), a linear operation equation such as involved in potential problems may be solved using the Best Approximation Method by use of the inner product $$\rm(u,v)= \ \int\limits_\Gamma \ uvd\Gamma + \ \int\limits_\Omega \ Lu \ Lv \ d\Omega$$ (7.1.1) where the integration over Γ includes both the spatial and temporal boundary conditions (i.e., initial conditions in a diffusion problem).

There is no unique stationary scattering theory. We distinguish the main versions by analyzing the different idealizations (spatial or temporal boundary conditions - SBC and TBC, respectively) implied by different orders of taking the limits of infinite volume and of sharp initial conditions. The relations of the different representations are discussed in detail. The equivalence of the Schrödinger and Heisenberg dynamical pictures, as well as the hermiticity of the Hamiltonian fail for SBC but can be applied in TBC. However, when using TBC the scattering wave does not behave as an eigenfunction of the Hamiltonian. The evaluation of transition rates and rates of change of observables is described for the different approaches. We also distinguish the meaning of two types of invariants of the motion by resolving the temporal variation of the observables as an "internal" production rate plus a term representing the flux across the boundary of the scattering region.

The corner problem is a century-old canonical scattering problem describing wave diffraction at a quarter-plane spatial discontinuity. Here, we study its space-time analog: wave scattering at a corner in space-time, arising at a time-switched spatial interface. We highlight and resolve an inconsistency between spatial and temporal boundary conditions arising in this problem, and analytically demonstrate the emergence of shock waves launched by the scattering process. After numerically verifying our theory, we realize and experimentally probe the scattering at a space-time corner arising at the edge of a time-switched waveguide. Our results unveil and efficiently model the unusual phenomena arising at the spatial interface between time-modulated and static media, of great relevance for the growing field of spatiotemporal metamaterials.

In topological terms, we compute the spectral flow of an arbitrary family of self-adjoint Dirac-type operators with classical (local) boundary conditions on a compact Riemannian manifold with boundary under the assumption that the initial and terminal operators of the family are conjugate by an automorphism of the bundle in which the operators act. We use this result to study conditions for the existence of a nonzero spectral flow of a family of self-adjoint Dirac-type operators with local boundary conditions in a two-dimensional domain with a nontrivial topology and discuss possible physical realizations of a nonzero spectral flow.

Climate change affects river deltas worldwide. Hydrodynamic models are used to study these effects. However, choosing the spatial scale and boundary conditions for these models is complex due to interconnectivity within river deltas. We study how boundary conditions of a model covering only part of such systems are impacted by changing conditions outside of the domain. We couple different components of the Dutch river delta into a model covering the complete delta, and force it with a range of river discharges and sea levels. Results show that the impact depends on the distance to the boundaries, as well as the relative (upstream) discharge in the considered rivers. As these differences are found to propagate far upstream, these findings underline the importance of choosing appropriate downstream boundaries when modelling water levels in parts of interconnected systems influenced by changing conditions outside the modelled domain (e.g. sea level rise or changing hydrographs). • Modelling part of a river delta does not capture relevant interactions within deltas. • Extending the modelling domain reduces the impact of uncertain boundary conditions. • Impact of uncertain boundary conditions increases for decreasing upstream discharge. • Stage-discharge relations are strongly impacted by climate change scenarios.

Microblogging services have become among the most popular services on the web in the last few years. This led to significant increase in data size, speed, and applications. This paper presents Venus ; a system that supports real-time spatial queries on microblogs. Venus supports its queries on a spatial boundary $R$ and a temporal boundary $T$ , from which only the top- $k$ microblogs are returned in the query answer based on a spatio-temporal ranking function. Supporting such queries requires Venus to digest hundreds of millions of real-time microblogs in main-memory with high rates, yet, it provides low query responses and efficient memory utilization. To this end, Venus employs: (1) an efficient in-memory spatio-temporal index that digests high rates of incoming microblogs in real time, (2) a scalable query processor that prune the search space, $R$ and $T$ , effectively to provide low query latency on millions of items in real time, and (3) a group of memory optimization techniques that provide system administrators with different options to save significant memory resources while keeping the query accuracy almost perfect. Venus memory optimization techniques make use of the local arrival rates of microblogs to smartly shed microblogs that are old enough not to contribute to any query answer. In addition, Venus can adaptively, in real time, adjust its load shedding based on both the spatial distribution and the parameters of incoming query loads. All Venus components can accommodate different spatial and temporal ranking functions that are able to capture the importance of each dimension differently depending on the applications requirements. Extensive experimental results based on real Twitter data and actual locations of Bing search queries show that Venus supports high arrival rates of up to 64 K microblogs/second and average query latency of 4 msec.

Education is one of the fundamental pillars of human and economic development, and government spending on the education sector is viewed as a long-term investment in human capital. The higher the level and quality of education, the greater the efficiency and productivity of the workforce, which positively impacts economic and social growth rates. From this perspective, this research seeks to analyze the relationship between government spending on education and labor productivity in Iraq during the period (2004–2022), focusing on the extent to which this spending impacts educational outcomes and their alignment with labor market requirements.

We study the manifestly exotic tetraquark D •• s0 ´cu s dµ and the scalar tetraquark f 0 ´ud ū dµ in SU(3) c anisotropic quenched lattice QCD.We adopt the O´aµ-improved Wilson (clover) fermion compact 4Q resonance is almost unchanged.In HBC, we find a nontrivial 4Q resonance state about 100 MeV below the two-meson threshold in some quark-mass region.Its chiral behavior largely differs from a two-meson scattering state.The scalar tetraquark f 0 ´ud ū dµ is found to have the mass of about 1.1GeV after chiral extrapolation, and seems to correspond to f 0 ´980µ.Then, the manifestly exotic tetraquark D •• s0 ´cu s dµ would exist around 1GeV in the idealized SU(4) f chiral limit.Finally, MEM analysis is applied to obtain the spectral function of the 4Q system.

As a western boundary current, the Kuroshio is closely related to the large-scale oceanic circulation and at the same time, is greatly influenced by the local topography because of its narrow width. Numerical studies of the Kuroshio are usually confined to portions of it in different geographical regions since the computer execution time required to run a numerical model of the Pacific using a sufficiently fine grid to resolve adequately the flow structure of the Kuroshio is enormous. In order to circumvent the problems of multiple spatial scales and consistent boundary conditions, nested models are employed in which a coarse grid model of the Pacific is used to supply the open boundary conditions for a finer grid model of the northwestern Pacific to simulate the flow and temperature fields of the Kuroshio in summer and winter. The major features of the Kuroshio have in general been successfully simulated by the nested models.

Motivated by the unique physical properties of biological active matter, e.g., cytoskeletal dynamics in eukaryotic cells, we set up effective two-dimensional (2d) coarse-grained hydrodynamic equations for the dynamics of thin active gels with polar or nematic symmetries. We use the well-known three-dimensional (3d) descriptions (K. Kruse et al., Eur. Phys. J. E 16, 5 (2005); A. Basu et al., Eur. Phys. J. E 27, 149 (2008)) for thin active-gel samples confined between parallel plates with appropriate boundary conditions to derive the effective 2d constitutive relations between appropriate thermodynamic fluxes and generalised forces for small deviations from equilibrium. We consider three distinct cases, characterised by spatial symmetries and boundary conditions, and show how such considerations dictate the structure of the constitutive relations. We use these to study the linear instabilities, calculate the correlation functions and the diffusion constant of a small tagged particle, and elucidate their dependences on the activity or nonequilibrium drive.

The Po Valley (Italy) model inter-comparison exercise (POMI) has been carried out in order to explore the changes in air quality in response to changes in emissions. The starting point was the evaluation of the simulated particulate matter and ozone (O3) modelled concentrations against observations for the year 2005 of the six participating chemical transport models. As models were run with the same configuration in terms of spatial resolution, boundary condition, emissions and meteorology, the differences presented in the models’ results are only related to their formulation. As described in the paper, significant efforts have been made to improve the accuracy of the anthropogenic emissions and meteorological input data. Nevertheless, none of the models using the proposed meteorology succeeded to fulfil the quality performance criteria set in the 2008 Air Quality Directive and in the literature for particulate matter, while also for ozone the results are not very satisfying. Although the overall performances look better for O3 than for particulate matter with an aerodynamic diameter smaller than 10 μm (PM10), the models tend to exhibit a similar behaviour and show the largest model variability in locations where concentrations are the highest (urban areas for PM10 and suburbs and hilly areas for O3). While differences are significant in terms of standard deviation and bias, the correlation remains quite similar among models indicating that models generally capture well the main temporal variations, especially the seasonal ones. Possible explanations for this common behaviour and a discussion of the differences among models’ results are presented in this paper.

Surface effects on a diffusion process governed by a fractional diffusion equation in a confined region with spatial and time dependent boundary conditions are investigated. First, we consider the one-dimensional case with the boundary conditions rho(0,t)=Phi0(t) and rho(a,t)=Phia(t). Subsequently, the two-dimensional case in the cylindrical symmetry with rho(a,theta,t)=Phia(theta,t) and rho(b,theta,t)=Phib(theta,t) is investigated. For these cases, we also obtain exact solutions for an arbitrary initial condition by using the Green's function approach.