6,965 research outputs found
Post-Newtonian Approximation of Teleparallel Gravity Coupled with a Scalar Field
We use the parameterized post-Newtonian (PPN) formalism to explore the weak
field approximation of teleparallel gravity non-minimally coupling to a scalar
field , with arbitrary coupling function and potential
. We find that all the PPN parameters are identical to general
relativity (GR), which makes this class of theories compatible with the Solar
System experiments. This feature also makes the theories quite different from
the scalar-tensor theories, which might be subject to stringent constraints on
the parameter space, or need some screening mechanisms to pass the Solar System
experimental constraints.Comment: 15 pages, revtex4; v2: discussions added, Nucl. Phys. B in press; v3:
published versio
Bis(4′-chloro-2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)iron(II) dinitrate dihydrate
The title complex, [Fe(C15H10ClN3)2](NO3)2·2H2O, has a six-coordinate iron(II) center balanced by two nitrate anions. The Fe atom lies on a twofold rotation axis. The complex exhibits an octaÂhedral coordination configuration, where the dihedral angle between the two planar tridentate ligands is 92.4 (1)°. The crystal structure involves O—H⋯O hydrogen bonds
Fractional Path Integrals and its degeneration to Dimensional Regularization
In this work we study particles propagate in a fractional path and use
fractional derivatives to extend the dynamic dimension of Quantum Field Theory.
we construct the Lagrangian of fractional scalar, vector and spinor fields to
obtain their propagators by path integral. Then we compute the typical tree
level and one loop diagrams which correspond to QED cases. The calculations
show the dimension dependence of amplitudes. Additionally, in one loop
calculation we obtain results which are consistent with dimensional
regularization as the dimension approaches to the Standard Model value.
Therefore, the fractional Path Integrals can be regarded as an equivalent
theoretical representation for regularizing the divergence in the normal
Quantum Field Theory. We also derive the equation of motion for scalar, vector
and spinor particles propagate in fractal paths and discuss the corresponding
gauge symmetry, where we find a special non-local gauge transformation.Comment: 17page
Co-gasification of woody biomass and chicken manure: Syngas production, biochar reutilization, and cost-benefit analysis
The management and disposal of livestock manure has become one of the top environmental issues at a global scale in line with the tremendous growth of poultry industry over the past decades. In this work, a potential alternative method for the disposal of chicken manure from Singapore local hen layer farms was studied. Gasification was proposed as the green technology to convert chicken manure into clean energy. Through gasification experiments in a 10 kW fixed bed downdraft gasifier, it was found that chicken manure was indeed a compatible feedstock for gasification in the presence of wood waste. The co-gasification of 30 wt% chicken manure and 70 wt% wood waste produced syngas of comparable quality to that of gasification of pure wood waste, with a syngas lower heating value (LHV) of 5.23 MJ/Nm3 and 4.68 MJ/Nm3, respectively. Furthermore, the capability of the gasification derived biochar in the removal of an emerging contaminant (artificial sweetener such as Acesulfame, Saccharin and Cyclamate) via adsorption was also conducted in the second part of this study. The results showed that the biochar was effective in the removal of the contaminant and the mechanism of adsorption of artificial sweetener by biochar was postulated to be likely via electrostatic interaction as well as specific interaction. Finally, we conducted a cost-benefit analysis for the deployment of a gasification system in a hen layer farm using a Monte Carlo simulation model
Cooperative Multi-Objective Reinforcement Learning for Traffic Signal Control and Carbon Emission Reduction
Existing traffic signal control systems rely on oversimplified rule-based
methods, and even RL-based methods are often suboptimal and unstable. To
address this, we propose a cooperative multi-objective architecture called
Multi-Objective Multi-Agent Deep Deterministic Policy Gradient (MOMA-DDPG),
which estimates multiple reward terms for traffic signal control optimization
using age-decaying weights. Our approach involves two types of agents: one
focuses on optimizing local traffic at each intersection, while the other aims
to optimize global traffic throughput. We evaluate our method using real-world
traffic data collected from an Asian country's traffic cameras. Despite the
inclusion of a global agent, our solution remains decentralized as this agent
is no longer necessary during the inference stage. Our results demonstrate the
effectiveness of MOMA-DDPG, outperforming state-of-the-art methods across all
performance metrics. Additionally, our proposed system minimizes both waiting
time and carbon emissions. Notably, this paper is the first to link carbon
emissions and global agents in traffic signal control.Comment: arXiv admin note: substantial text overlap with arXiv:2205.1129
A Convenient Adomian-Pade Technique for the Nonlinear Oscillator Equation
Very recently, the convenient way to calculate the Adomian series was suggested. This paper combines this technique and the Pade approximation to develop some new iteration schemes. Then, the combined method is applied to nonlinear models and the residual functions illustrate the accuracies and conveniences
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