44 research outputs found

    Water Quality Modeling and Field Investigations in Southeast Lagoon of Caspian Sea

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Exploring Modifications to FLRW Cosmology with General Entropy and Thermodynamics: A new Approach

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    This paper investigates modifications to the FLRW cosmology resulting from considering general entropy for the cosmological apparent horizon. Although the Bekenstein-Hawking entropy has been successful in the study of the thermodynamics of black holes and cosmology, according to the laws of thermodynamics, considering this entropy, it imposes a w=1w=-1 limit on the equation of state of the cosmic fluid. To address this limitation, Nojiri and colleagues in 2022, introduced generalized entropies with four-parameters that may tend to familiar entropies and can solve some problems of cosmology. In this paper, we explore how correcting the entropy affects the Energy-momentum tensor of the cosmic flux from the outset. Our calculations show that in any way, the modified Bekenstein-Hawking entropy can be still considered as a general entropy after a modification energy-momentum density tensor with a correction function f(ρ)f(\rho). The function f(ρ)f(\rho) can be easily reconstructed, by considering the thermodynamics of the apparent horizon. We also study the first and second laws of thermodynamics in this context and show how the problem of limited cosmic flux can be resolved based on the model's parameters. At last, In order to study the kinematics of the universe, cosmography parameters are also calculated and we see that the correction function f(ρ)f(\rho) has a non-negligible role in cosmography parameters. This paper provides valuable insights into using general entropies on the apparent horizon of the universe.Comment: 12 page

    Estimation of Impulse Wave Run-up Caused by Underwater Landslide in Dam Reservoirs

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Medial patellofemoral ligament (MPFL) reconstruction surgery in Iranian patients with recurrent patellar dislocation: Report of three years experiences

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    Reconstruction of the medial patellofemoral ligament (MPFL) is reported as recent and challengeable treatment approach for recurrent patellar dislocation. There is no complete study with suitable follow-up time on Iranian patients with recurrent patellar dislocation and assessment outcome of MPFL reconstruction with patellar suture anchor(PSA) technique. Present clinical survey, summarized three years experiences of MPFL reconstruction with patellar suture anchor technique and clinical features in Iranian patients with recurrent patella dislocation and related topics in our university hospital. Present retrospective clinical survey had been performed on 23 patients with patellar recurrent dislocation that had MPFL reconstruction between March 2010 and May 2013. MPFL reconstruction was performed by one orthopedic surgeon in a university hospital. Patellar Apprehension test, Standard Kujala Score and knee range of motion measurement had been performed before and after MPFL recostruction and its results were inserted into the checklist after at least 12 months follow-up. During follow-up with average of 17.4 months, there was no patellar dislocation or subluxation and patellar apprehension test was negative among all of patients. The patients reach to their full flexion (10.83 weeks in male and 9.77 weeks in female) and extension (3.33 weeks) in their knee joints postoperatively. Mean of Kujala score in the patients had been significantly improved after MPFL reconstruction (from 59.8 to 88.6). Patellar fracture was not seen. Findings of our study suggested that outcome of MPFL reconstruction surgery using two anchor suture in treatment of recurrent patellar dislocation is good and successful

    Optimal Bidding Strategies in Network-Constrained Demand Response: A Distributed Aggregative Game Theoretic Approach

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    Demand response has been a promising solution for accommodating renewable energy in power systems. In this study, we consider a demand response scheme within a distribution network facing an energy supply deficit. The utility company incentivizes load aggregators to adjust their pre-scheduled energy consumption and generation to match the supply. Each aggregator, which represents a group of prosumers, aims to maximize its revenue by bidding strategically in the demand response scheme. Since aggregators act in their own self-interest and their revenues and feasible bids influence one another, we model their competition as a network-constrained aggregative game. This model incorporates power flow constraints to prevent potential line congestion. Given that there are no coordinators and aggregators can only communicate with their neighbours, we introduce a fully distributed generalized Nash equilibrium seeking algorithm to determine the optimal bidding strategies for aggregators in this game. Within this algorithm, only estimates of the aggregate and certain auxiliary variables are communicated among neighbouring aggregators. We demonstrate the convergence of this algorithm by constructing an equivalent iteration using the forward-backward splitting technique

    Disturbance decoupling problem for multi-agent systems:A graph topological approach

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    Çamlıbel, Mehmet Kanat (Dogus Author)This paper studies the disturbance decoupling problem for multi-agent systems with single integrator dynamics and a directed communication graph. We are interested in topological conditions that imply the disturbance decoupling of the network, and more generally guarantee the existence of a state feedback rendering the system disturbance decoupled. In particular, we will develop a class of graph partitions, which can be described as a "topological translation" of controlled invariant subspaces in the context of dynamical networks. Then, we will derive sufficient conditions in terms of graph partitions such that the network is disturbance decoupled, as well as conditions guaranteeing solvability of the disturbance decoupling problem. The proposed results are illustrated by a numerical example

    Thermodynamics of Taub-NUT/Bolt-AdS Black Holes in Einstein-Gauss-Bonnet Gravity

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    We give a review of the existence of Taub-NUT/bolt solutions in Einstein Gauss-Bonnet gravity with the parameter α\alpha in six dimensions. Although the spacetime with base space S2×S2S^{2}\times S^{2} has curvature singularity at r=Nr=N, which does not admit NUT solutions, we may proceed with the same computations as in the CP2\mathbb{CP}^{2} case. The investigation of thermodynamics of NUT/Bolt solutions in six dimensions is carried out. We compute the finite action, mass, entropy, and temperature of the black hole. Then the validity of the first law of thermodynamics is demonstrated. It is shown that in NUT solutions all thermodynamic quantities for both base spaces are related to each other by substituting αCPk=[(k+1)/k]αS2×S2×>...Sk2\alpha^{\mathbb{CP}^{k}}=[(k+1)/k]\alpha^{S^{2} \times S^{2}\times >...S_{k}^{2}}. So no further information is given by investigating NUT solution in the S2×S2S^{2}\times S^{2} case. This relation is not true for bolt solutions. A generalization of the thermodynamics of black holes to arbitrary even dimensions is made using a new method based on the Gibbs-Duhem relation and Gibbs free energy for NUT solutions. According to this method, the finite action in Einstein Gauss-Bonnet is obtained by considering the generalized finite action in Einstein gravity with an additional term as a function of α\alpha. Stability analysis is done by investigating the heat capacity and entropy in the allowed range of α\alpha, Λ\Lambda and NN. For NUT solutions in dd dimensions, there exist a stable phase at a narrow range of α\alpha. In six-dimensional Bolt solutions, metric is completely stable for B=S2×S2\mathcal{B}=S^{2}\times S^{2}, and is completely unstable for B=CP2\mathcal{B}=\mathbb{CP}^{2} case.Comment: 19 pages, 3 figures, some Refs. are added, Fig 1 is replaced, and some corrections are don
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