Virginia Mason Medical Center, founded in 1920, is a private, non-profit organization located in Seattle, Washington, US.
We discuss the existence, uniqueness, Ulam-Hyer's stability, and Trajectory (T-) controllability for solutions of coupled nonlinear fractional order stochastic differential systems (FSDEs) with integral boundary conditions via integral contractors. Using Banach space, we obtain some relaxed conditions for existence and uniqueness for the mentioned problem via successive approximation techniques. Furthermore, to demonstrate the results, the concept of bounded integral contractors is combined with a fractional order coupled system using regularity conditions. The Green's function is used to find the solution for the coupled system with boundary conditions. Through Integral Contractors (ICs), we examine the existence and uniqueness results for a higher-order nonlinear fractional coupled stochastic system with integral boundary conditions on Time Scales. Further, we develop some conditions for Ulam-Hyer's stability for the non-linear fractional order coupled systems. To demonstrate our main result, we provide a proper example. The real-life application of a coupled fractional stochastic Kelvin-Voigt model on viscoelastic elastomer is investigated to justify the theoretical model with the numerical comparison with a single and a double fractional stochastic Kelvin-Voigt model.
The main concern of the manuscript deals with the optimal control problem of conformable fractional neutral stochastic integrodifferential systems with infinite delay. This study is motivated by SAR and RAR systems advantage of providing control over many factors such as power, frequency, phase, polarization, incidence angle, spatial resolution and swath width, all of which are important when designing and operating a radar system. Initially, we investigate the existence of mild solutions for the conformable fractional stochastic integrodifferential equations with infinite delay using stochastic analysis techniques and Banach fixed point theorem. In the later part we establish the existence of mild solutions of the conformable fractional neutral stochastic integrodifferential system with infinite time delay. Furthermore, the existence of optimal control of the corresponding Lagrange optimal control problem is investigated. An example is provided to illustrate the applications of the obtained results. We explain the limitation we have with the existence software, and developed a numerical scheme to justify the theory.
Efficient modeling of the complex dynamics between flow physics and chemical kinetics during flame propagation is crucial for understanding combustion mechanisms in real-world applications such as propulsion, energy conversion, and emission control. A two-dimensional, high-order, compact finite difference computational fluid dynamics (CFD) code in cylindrical coordinates has been developed to investigate the interaction between flow and chemistry in a laminar non-premixed flame. The numerical framework (implemented in Fortran) employs a fifth-order scheme for convective terms and a fourth-order scheme for viscous terms to enhance the resolution of steep gradients characteristic of reacting flows. Conversely, a fourth-order Runge-Kutta (RK4) time integration scheme improves solution stability and reduces the convergence error by approximately 20% compared to the simpler Euler-forward (EF) method. To accurately capture the intricate coupling between flow and chemistry, the steady flamelet model (SFM) with detailed kinetics is incorporated into the CFD framework, enabling a reduced yet robust representation of chemical kinetics. The model is validated against benchmark experimental and numerical datasets, demonstrating strong agreement and predictive capability, with 60% and 15% lower Root Mean Squared Error (RMSE) for temperature and H2O mole fraction, compared to the species-transport-based numerical results. A systematic parametric study was conducted using a canonical co-flow laminar methane-air diffusion flame configuration. The effects of varying Reynolds number, fuel-to-air velocity ratio, and combustor geometry are analyzed in detail. The study reveals that increasing the combustor length leads to more anchored and spatially confined flame structures. Additionally, the study demonstrates that increasing the inner diameter enhances radial diffusion, resulting in more dispersed flame fronts. These findings underscore the role of combustor geometry in optimizing designs for both efficiency and emissions control. Furthermore, the proposed higher-order scheme advances reactive flow modeling by offering a validated and computationally efficient tool for high-resolution simulations of chemically reacting flows.
The thermal conductivity of battery components has become an important factor for predicting the temperature distribution within battery cells during their operation. The importance of this increases with a growing cell size and is especially important for prismatic hard case cells. However, its determination is still in an early stage, and different measurement approaches provide largely varying results. Herein, the thermal conductivity of electrode coatings is investigated by measuring the through-plane thermal conductivity of electrode stacks. For this, the laser flash analysis (LFA) and guarded hot plate (GHP) method are used as common measuring approaches for battery components. A comparison of the different methods for different active materials, porosities, and electrode thicknesses is conducted and confirmed the strong variations between the two methods seen in the literature. Both methods have their challenges and limitations, where the most important is that LFA is best for thin and low-porous electrodes and that the GHP is best for thick and high-porous electrodes. The study discusses these and other effects around in greater detail.
This paper examines the effects of mindfulness training on students attending a senior military college in the United States. In a 4-week pilot study (n = 31) and a subsequent in-depth 8-week study (n = 66, 18 women), participants were randomly assigned to a mindfulness training group (MG) or a nutrition training control group (CG). Each group completed a 60 min weekly training workshop, 20 min of daily homework for the remaining 6 days, brief journal entries about the homework, and seven assessments at the start and the conclusion of the study. The duration, frequency, and intensity of training of the intervention and control group were identical. Results indicate a significant decrease in stress in the MG and no change in the CG. The MG also reported a significant increase in their overall score on the Five Facet Mindfulness Questionnaire as well as the Observing, Describing, and Nonreactivity sub scores. CG changes did not reach significance on any of these variables. The sleep quality score on the Pittsburgh Sleep Quality Index (PSQI) indicated improved sleep quality for the MG but not the CG. The PSQI sleep efficiency score indicated lower sleep efficiency for the CG but not the MG. Findings demonstrate the effectiveness of mindfulness training for lowering stress levels, improving sleep quality, and increasing the frequency of behaviors associated with positive mental health such as nonreactivity in a student body that experiences the stresses from both the academic and military rigor that characterizes senior military colleges.
