Extended Phase Research Articles

Safety and Efficacy of a Composite Lipid Emulsion with Fish Oil in Hospitalized Neonates and Infants Requiring Prolonged Parenteral Nutrition - A Randomized, Double-Blind, Multicenter, Controlled Trial

BackgroundIntravenous lipids are critical to the care of extremely premature and other high-risk infants. ObjectiveThe study evaluated safety and efficacy of parenteral nutrition (PN) with composite intravenous lipid emulsion (CO-ILE) with fish oil compared to pure soybean oil lipid emulsion (SOLE). MethodsRandomized, controlled, double-blind, multicenter study (NCT02579265) in neonates/ infants anticipated to require ≥28 days of PN due to gastrointestinal malformations or injury. Duration of the initial and extended treatment phase was 28 days and 84 days (for patients with PN indication after day 28). Results83/ 78 patients (mean postnatal age: 11.4/ 8.3 days, 54/ 59 preterm) received CO-ILE and SOLE, respectively. 33 patients per group completed 28 days on treatment. Risk of having conjugated bilirubin values > 2 mg/dL confirmed by a second sample 7 days after the first during the initial treatment phase (primary outcome) was 2.4% (2 of 83) with CO-ILE and 3.8% (3 of 78) with SOLE (risk ratio 0.59 [95% CI: 0.09, 3.76]). Between days 29 and 84, the number of patients with confirmed conjugated bilirubin values > 2 mg/dL did not increase in the CO-ILE group (n=2) and increased in the SOLE group (n=9). At the end of the initial treatment phase, conjugated bilirubin concentrations were 45.6% lower under CO-ILE than under SOLE (p=0.006). There was no clinical or laboratory evidence of essential fatty acid deficiency in patients in the CO-ILE group. Median time to discharge alive was 56.7 and 66.4 days with CO-ILE and SOLE, respectively (hazard ratio: 1.16; 95% CI: 0.81, 1.68). ConclusionsCO-ILE was associated with a possible lower risk of cholestasis and significantly lower conjugated bilirubin at the end of the initial treatment phase in high-risk neonates and infants as compared to patients treated with SOLE. In summary, these data indicate that CO-ILE can be considered safe and may be preferable over SOLE in high-risk neonates.Clinical Trial Registry number: Clinicaltrials.gov, study ID NCT02579265

Intrinsically safe DAB converter for reliable power supply in harsh environment via extended phase shift pulse train control

AbstractIn this article, an extended‐phase‐shift‐based pulse train control (EPS‐PT) for an intrinsically safe dual active bridge (DAB) converter is proposed to satisfy the safe and reliable power supply in harsh environments such as gas stations, chemical plants, and mining tunnels in complex power systems. A discrete pulse switching control method is introduced, and the input voltage and output current are sampled to calculate the primary target phase shift angle of the DAB converter, followed by the inner phase shift angle, while the secondary phase shift angle is rapidly adjusted by the voltage feedback. In order to meet the requirements of effective control and safe power supply in harsh environments, the system parameters are designed by comprehensively considering the control performance and intrinsically safe requirements. The simulation and experimental results demonstrate that the proposed DAB converter exhibits rapid dynamic response and intrinsic operation safety.

Thermodynamic properties and geometries of bardeen black hole surrounded by string clouds

In this work, we investigate the thermodynamic properties of Bardeen black hole which is coupled with cloud of strings and minimally coupled to nonlinear electrodynamics. The modified entropy in the form of Sharma–Mittal entropy is used to discuss these properties which include mass, temperature, pressure, Gibbs free energy and trace of Hessian matrix. We obtain stable behavior along with physical solution for some specific values of parameters a and q. Furthermore, our work provides a thermodynamic metric using the Hessian matrix of black hole mass, changing the conformal connection between Quevedo and Ruppeiner’s geometries. Investigating the first principle of thermodynamics for regular black holes, such as the Bardeen AdS black hole, exposes significant behavior changes during phase transitions in an extended phase space.

Realizations and star-product of doubly κ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa $$\\end{document}-deformed Yang models

The Yang algebra was proposed a long time ago as a generalization of the Snyder algebra to the case of curved background spacetime. It includes as subalgebras both the Snyder and the de Sitter algebras and can therefore be viewed as a model of noncommutative curved spacetime. A peculiarity with respect to standard models of noncommutative geometry is that it includes translation and Lorentz generators, so that the definition of a Hopf algebra and the physical interpretation of the variables conjugated to the primary ones is not trivial. In this paper we consider the realizations of the Yang algebra and its κ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\kappa $$\\end{document}-deformed generalization on an extended phase space and in this way we are able to define a Hopf structure and a twist.

Thermodynamics of Magnetic Black Holes with Nonlinear Electrodynamics in Extended Phase Space

We study Einstein’s gravity in AdS space coupled to nonlinear electrodynamics. Thermodynamics in extended phase space of magnetically charged black holes is investigated. We compute the metric and mass functions and their asymptotics, showing that black holes may have one or two horizons. The metric function is regular, f(0)=1, and corrections to the Reissner–Nordström solution are in the order of O(r−3) when the Schwarzschild mass is zero. We prove that the first law of black hole thermodynamics and the generalized Smarr relation hold. The magnetic potential and vacuum polarization conjugated to coupling are computed and depicted. We calculate the Gibbs free energy and the heat capacity showing that first-order and second-order phase transitions take place.

Parallel MCMC algorithms: theoretical foundations, algorithm design, case studies

Abstract Parallel Markov Chain Monte Carlo (pMCMC) algorithms generate clouds of proposals at each step to efficiently resolve a target probability distribution $\mu $. We build a rigorous foundational framework for pMCMC algorithms that situates these methods within a unified ‘extended phase space’ measure-theoretic formalism. Drawing on our recent work that provides a comprehensive theory for reversible single-proposal methods, we herein derive general criteria for multiproposal acceptance mechanisms that yield ergodic chains on general state spaces. Our formulation encompasses a variety of methodologies, including proposal cloud resampling and Hamiltonian methods, while providing a basis for the derivation of novel algorithms. In particular, we obtain a top-down picture for a class of methods arising from ‘conditionally independent’ proposal structures. As an immediate application of this formalism, we identify several new algorithms including a multiproposal version of the popular preconditioned Crank–Nicolson (pCN) sampler suitable for high- and infinite-dimensional target measures that are absolutely continuous with respect to a Gaussian base measure. To supplement the aforementioned theoretical results, we carry out a selection of numerical case studies that evaluate the efficacy of these novel algorithms. First, noting that the true potential of pMCMC algorithms arises from their natural parallelizability and the ease with which they map to modern high-performance computing architectures, we provide a limited parallelization study using TensorFlow and a graphics processing unit to scale pMCMC algorithms that leverage as many as 100k proposals at each step. Second, we use our multiproposal pCN algorithm (mpCN) to resolve a selection of problems in Bayesian statistical inversion for partial differential equations motivated by fluid measurement. These examples provide preliminary evidence of the efficacy of mpCN for high-dimensional target distributions featuring complex geometries and multimodal structures.

Extension of the BDS IGSO and MEO satellite antenna patterns with FengYun-3C and LuTan-1 onboard data

The International Global Navigation Satellite System (GNSS) Service (IGS) has recommended calibrating the extended satellite antenna Phase Center Variation (PCV) model for all navigation satellites to support low-Earth-Orbit (LEO) satellite applications. Owing to the absence of ground-calibrated PCVs for the BeiDou Navigation Satellite System (BDS), tracking data from global ground stations were used for in-orbit estimations. However, limited by the observed maximum nadir angle, PCVs based on ground data cannot cover the entire range of nadir angles observed using by LEO satellites. In this study, the FengYun-3C and LuTan-1 missions were used to extend the PCVs of the BDS Inclined GeoSynchronous orbit (IGSO) and medium-Earth-orbit (MEO) satellites. The PCVs corresponding to the ionosphere-free linear combinations of B1I/B2I, B1I/B3I, and B1C/B2a were calibrated in-orbit by extending the maximum nadir angle from 9° to 10° for the IGSO and from 13° to 15° for the MEO. There was good consistency among the estimated PCVs of satellites of the same type. In addition, these estimated PCVs were close to the corresponding satellite block-specific values estimated based on ground tracking data. The impact of the extended PCVs of the BDS satellite antenna was investigated by comparing them with the unextended PCVs model in the receiver antenna PCVs pattern estimation and precise orbit determination of the FengYun-3C and LuTan-1 satellites. The results showed that the extended BDS satellite PCVs effectively reduced the unmodeled error of the unextended BDS satellite PCVs in the low-elevation region of the LEO receiver antenna PCV patterns. In addition, compared with the introduction of phase center offset alone, the introduction of ground-based PCVs can improve the overlapping orbit differences (OODs) of LEO satellites, and the extended BDS satellite PCVs can further improve the OODs. Taking B1C/B2a as an example, the improvement ratio of OODs in the 3D direction of Lutan-1A increased from 5.2 % to 8.0 %, and that of Lutan-1B can rise from 1.7 % to 4.2 %.

BdRCN4, a Brachypodium distachyon TFL1 homologue, is involved in regulation of apical meristem fate.

In higher plants, the shift from vegetative to reproductive development is governed by complex interplay of internal and external signals. TERMINALFLOWER1 (TFL1) plays a crucial role in the regulation of flowering time and inflorescence architecture in Arabidopsis thaliana. This study aimed to explore the function of BdRCN4, a homolog of TFL1 in Brachypodium distachyon, through functional analyses in mutant and transgenic plants. The results revealed that overexpression of BdRCN4 in B. distachyon leads to an extended vegetative phase and reduced production of spikelets. Similar results were found in A. thaliana, where constitutive expression of BdRCN4 promoted a delay in flowering time, followed by the development of hypervegetative shoots, with no flowers or siliques produced. Our results suggest that BdRCN4 acts as a flowering repressor analogous to TFL1, negatively regulating AP1, but no LFY expression. To further validate this hypothesis, a 35S::LFY-GR co-transformation approach on 35::BdRCN4 lines was performed. Remarkably, AP1 expression levels and flower formation were restored to normal in co-transformed plants when treated with dexamethasone. Although further molecular studies will be necessary, the evidence in B. distachyon support the idea that a balance between LFY and BdRCN4/TFL1 seems to be essential for activating AP1 expression and initiating floral organ identity gene expression. This study also demonstrates interesting conservation through the molecular pathways that regulate flowering meristem transition and identity across the evolution of monocot and dicot plants.

Extended phase space thermodynamics of magnetized black holes with nonlinear electrodynamics

Einstein’s gravity in AdS space coupled to nonlinear electrodynamics (NED) with two parameters is studied. We investigate magnetically charged black holes. The metric and mass functions and their asymptotic are obtained showing that black holes may have one or two horizons. Thermodynamics in extended phase space was studied and it was proven that the first law of black hole thermodynamics and the generalized Smarr relation hold. The magnetic potential and the vacuum polarization conjugated to coupling (NED parameter), are computed and depicted. We calculate the Gibbs free energy and heat capacity.

Jacobi group symmetry of Hamilton's mechanics

We show that diffeomorphisms of an extended phase space with time, energy, momentum and position degrees of freedom leaving invariant a symplectic 2-form and a degenerate orthogonal metric dt2, corresponding to the Newtonian time line element, locally satisfy Hamilton's equations up to the usual canonical transformation on the position-momentum subspace.

Satellite position and attitude estimation using an infrared earth sensor

Micro/nano-satellites are constrained by payload, size, and cost, making enhancements in design flexibility crucial, particularly for orbit and attitude determination systems. An effective strategy is the innovative utilization of existing sensors. This study investigates a novel application of Earth sensors for autonomous position and attitude determination enabling them as a viable option for autonomous navigation in low-cost micro/nano-satellites through computer vision technology. To address large resolution differences and distortions between sensed infrared images and reference maps, this paper presents a coarse-to-fine matching framework that integrates deep learning features and area-based registrations. First, CNN-based registration and optimization techniques are utilized for coarse registration. A modified VGG16 (M-VGG) and a multiscale pyramid information fusion (MPIF) module are employed to extract and describe deep abstract features, enhancing robustness. Subsequently, edge-based extended phase correlation is employed for fine registration. Finally, the ultimate position and attitude parameters are determined by integrating the results from coarse and fine registration. The effectiveness of the proposed scheme is validated using synthetic images. An analysis of 342 images demonstrates sub-pixel registration accuracy, with a root mean square error (RMSE) of 1.9322 km for position and 0.1185° for attitude.

Modified EPS Control and Topology Modification for Two-Stage Bidirectional AC-DC Converter for V2G Applications

Abstract For the two-stage bidirectional AC-DC converter applied to vehicle-to-grid (V2G), this paper studies the modulation strategy and the topology of the dual active bridge (DAB) converter in the DC-DC stage. Aiming at the problem of large circulating current due to the fixed internal phase shift under the traditional extended phase shift (EPS) control, this paper modified the EPS modulation strategy by deciding whether the internal phase shift is generated by the primary or secondary side based on the voltage gain, which realizes the high-efficiency power transfer under wide voltage gain. To realize the full load range zero voltage switching (ZVS) with junction capacitors taken into account, it is proposed to parallel an additional auxiliary inductor between the bridge arms of the DAB converter, and the operating mechanism and the improved effect are analyzed in detail. Finally, a simulation circuit was built using PSIM software to verify the correctness.

Matter relative to quantum hypersurfaces

We explore the canonical description of a scalar field in 1+1 dimensional Minkowski space as a parametrized field theory on an extended phase space that includes additional embedding fields that characterize spacetime hypersurfaces X relative to which the scalar field is described. This theory is quantized via the Dirac prescription and physical states of the theory are used to define conditional wave functionals |ψϕ[X]⟩ interpreted as the state of the field relative to the hypersurface X, thereby extending the Page-Wootters formalism to quantum field theory. It is shown that this conditional wave functional satisfies the Tomonaga-Schwinger equation, thus demonstrating the formal equivalence between this extended Page-Wootters formalism and standard quantum field theory. We also construct relational Dirac observables and define a quantum deparametrization of the physical Hilbert space leading to a relational Heisenberg picture, which are both shown to be unitarily equivalent to the Page-Wootters formalism. Moreover, by treating hypersurfaces as quantum reference frames, we extend recently developed quantum frame transformations to changes between classical and nonclassical hypersurfaces. This allows us to exhibit the transformation properties of a quantum field under a larger class of transformations, which leads to a frame-dependent particle creation effect. Published by the American Physical Society 2024

Bulk-boundary thermodynamics of charged black holes in higher-derivative theory

The connection between bulk and boundary thermodynamics in Einstein–Maxwell theory is well established using AdS/CFT correspondence. In the context of general higher-derivative gravity coupled to a U(1) gauge field, we examine the resemblance of the first law of thermodynamics between bulk and boundary, followed by an extended phase space description on both sides. Higher-derivative terms related to different powers of the string theory parameter α′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha '$$\\end{document} emerged from a consistent truncation in the bulk supergravity action. We demonstrate that one must include the fluctuation of α′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha '$$\\end{document} in the bulk thermodynamics as a bookkeeping tool to match the bulk first law and Smarr relation with the boundary side. Consequently, the Euler relation and the boundary first law are altered by adding two central charges (a,c).\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$({\ exttt{a}}, {\ exttt{c}}).$$\\end{document} To support our general conclusion, we consider the black hole in Gauss–Bonnet gravity and the general four-derivative theory. Finally, we examine the bulk and boundary aspects of the extended phase space description for higher-derivative-corrected black holes.

Current-sensorless model predictive control for DAB converter based on back-flow power optimization

To solve problems such as high back-flow power, low system efficiency and poor dynamic properties of dual-active-full-bridge DC-DC converters in energy routers under traditional single-phase-shift modulation, the present paper introduces a current-sensorless-based model predictive control method combining back-flow power optimization based on Extended-Phase-Shift (EPS) modulation strategy. The transmission power model of the DAB converter is analyzed, taking into account the extended phase shift and the optimal shift comparison combination is found by the Lagrange multiplier method with the return power as the objective function. Then, the cost function is constructed to track the output voltage to achieve model predictive control without a current sensor. Finally, the accuracy and efficiency of the proposed strategy are verified by simulation. The results demonstrate the efficacy of this approach in mitigating system back-flow power and enhancing dynamic performance.

Hamiltonian Computational Chemistry: Geometrical Structures in Chemical Dynamics and Kinetics.

The common geometrical (symplectic) structures of classical mechanics, quantum mechanics, and classical thermodynamics are unveiled with three pictures. These cardinal theories, mainly at the non-relativistic approximation, are the cornerstones for studying chemical dynamics and chemical kinetics. Working in extended phase spaces, we show that the physical states of integrable dynamical systems are depicted by Lagrangian submanifolds embedded in phase space. Observable quantities are calculated by properly transforming the extended phase space onto a reduced space, and trajectories are integrated by solving Hamilton's equations of motion. After defining a Riemannian metric, we can also estimate the length between two states. Local constants of motion are investigated by integrating Jacobi fields and solving the variational linear equations. Diagonalizing the symplectic fundamental matrix, eigenvalues equal to one reveal the number of constants of motion. For conservative systems, geometrical quantum mechanics has proved that solving the Schrödinger equation in extended Hilbert space, which incorporates the quantum phase, is equivalent to solving Hamilton's equations in the projective Hilbert space. In classical thermodynamics, we take entropy and energy as canonical variables to construct the extended phase space and to represent the Lagrangian submanifold. Hamilton's and variational equations are written and solved in the same fashion as in classical mechanics. Solvers based on high-order finite differences for numerically solving Hamilton's, variational, and Schrödinger equations are described. Employing the Hénon-Heiles two-dimensional nonlinear model, representative results for time-dependent, quantum, and dissipative macroscopic systems are shown to illustrate concepts and methods. High-order finite-difference algorithms, despite their accuracy in low-dimensional systems, require substantial computer resources when they are applied to systems with many degrees of freedom, such as polyatomic molecules. We discuss recent research progress in employing Hamiltonian neural networks for solving Hamilton's equations. It turns out that Hamiltonian geometry, shared with all physical theories, yields the necessary and sufficient conditions for the mutual assistance of humans and machines in deep-learning processes.

Screwon spectral statistics and dispersion relation in the quantum Rajeev–Ranken model

The Rajeev–Ranken (RR) model is a Hamiltonian system describing screw-type nonlinear waves (screwons) of wavenumber k in a scalar field theory pseudodual to the 1+1D SU(2) principal chiral model. Classically, the RR model based on a quadratic Hamiltonian on a nilpotent/Euclidean Poisson algebra is Liouville integrable. Upon adopting canonical variables in a slightly extended phase space, the model was interpreted as a novel 3D cylindrically symmetric quartic oscillator with a rotational energy. Here, we examine the spectral statistics and dispersion relation of quantized screwons via numerical diagonalization validated by variational and perturbative approximations. We also derive a semiclassical estimate for the cumulative level distribution which compares favorably with the one from numerical diagonalization. The spectrum shows level crossings typical of an integrable system. The ith unfolded nearest neighbor spacings are found to follow Poisson statistics for small i. Nonoverlapping spacing ratios also indicate that successive spectral gaps are independently distributed. After displaying universal linear behavior over energy windows of short lengths, the spectral rigidity saturates at a length and value that scales with the square-root of energy. For strong coupling λ and intermediate k, we argue that reduced screwon energies can depend only on the product λk. Numerically, we find power law dependences on λ and k with an approximately common exponent 2/3 provided the angular momentum quantum number l is small compared to the number of nodes n in the radial wavefunction. On the other hand, for the ground state n=l=0, the common exponent becomes 1.

On the extension of singular linear infinite-dimensional Hamiltonian flows

We study the phenomenon of phase trajectories of a Hamiltonian system going to infinity in a finite time, the phase space of which is a separable Hilbert space. It is shown that if the Hamiltonian is a densely defined quadratic form on the phase space, which is not majorized either from below or from above by the quadratic form of the Hilbert norm, then the phase trajectories allow going to infinity in a finite time. To describe the phase flow of such Hamiltonian systems, an extended phase space is introduced, which is a locally convex space to which the Hamiltonian function, trajectories of the Hamiltonian system, and the symplectic form defined on the original Hilbert space can be extended. Flowinvariant measures on extended space are also studied. The properties of the Koopman unitary representation of the extended phase flow in the Hilbert space of functions that are quadratically integrable with respect to an invariant measure are investigated.

Effect of scalar hair on magnetically charge Euler-Heisenberg AdS black hole via extended phase transition

In this article, we have studied numerous thermodynamical aspects and the extended phase space of the AdS magnetically charged Euler-Heisenberg BH minimally coupled to a scalar field. We investigated the ADM mass, Hawking temperature, entropy, specific heat, Gibss free energy (both locally and globally) and P-V criticality at the horizon radius. Our result shows that the maximum value for the Hawking temperature of the magnetically charged Euler-Heisenberg BHis reached at the point where the specific heat and free energy diverge, which is also the point at which the second-order phase transition takes place. We found that the magnetically charged Euler-Heisenberg BHis thermodynamically stable, with a positive heat capacity and negative Gibbs free energy. We also examined the extended second-order phase space of the considered BHin both ensembles.

Magnetic Black Hole Thermodynamics in an Extended Phase Space with Nonlinear Electrodynamics.

We study Einstein's gravity coupled to nonlinear electrodynamics with two parameters in anti-de Sitter spacetime. Magnetically charged black holes in an extended phase space are investigated. We obtain the mass and metric functions and the asymptotic and corrections to the Reissner-Nordström metric function when the cosmological constant vanishes. The first law of black hole thermodynamics in an extended phase space is formulated and the magnetic potential and the thermodynamic conjugate to the coupling are obtained. We prove the generalized Smarr relation. The heat capacity and the Gibbs free energy are computed and the phase transitions are studied. It is shown that the electric fields of charged objects at the origin and the electrostatic self-energy are finite within the nonlinear electrodynamics proposed.