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

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

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

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 $w=-1$ 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 $f(\rho)$. The function $f(\rho)$ 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 $f(\rho)$ 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

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

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

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

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

We give a review of the existence of Taub-NUT/bolt solutions in Einstein Gauss-Bonnet gravity with the parameter $\alpha$ in six dimensions. Although the spacetime with base space $S^{2}\times S^{2}$ has curvature singularity at $r=N$, which does not admit NUT solutions, we may proceed with the same computations as in the $\mathbb{CP}^{2}$ 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 $\alpha^{\mathbb{CP}^{k}}=[(k+1)/k]\alpha^{S^{2} \times S^{2}\times >...S_{k}^{2}}$. So no further information is given by investigating NUT solution in the $S^{2}\times S^{2}$ 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 $\alpha$. Stability analysis is done by investigating the heat capacity and entropy in the allowed range of $\alpha$, $\Lambda$ and $N$. For NUT solutions in $d$ dimensions, there exist a stable phase at a narrow range of $\alpha$. In six-dimensional Bolt solutions, metric is completely stable for $\mathcal{B}=S^{2}\times S^{2}$, and is completely unstable for $\mathcal{B}=\mathbb{CP}^{2}$ case.Comment: 19 pages, 3 figures, some Refs. are added, Fig 1 is replaced, and some corrections are don

Reconstruction of modified gravity with ghost dark energy models

In this work, we reconstruct the $f(R)$ modified gravity for different ghost and generalized ghost dark energy models in FRW flat universe, which describe the accelerated expansion of the universe. The equation of state of reconstructed $f(R)$ - gravity has been calculated. We show that the corresponding $f(R)$ gravity of ghost dark energy model can behave like phantom or quintessence. We also show that the equation of state of reconstructed $f(R)$ gravity for generalized ghost model can transit from quintessence regime to the phantom regime as indicated by recent observations.Comment: 13 pages, some references and one author are added. Accepted for publication by MPL