Signatures of two-step impurity mediated vortex lattice melting in Bose-Einstein Condensates

We simulate a rotating 2D BEC to study the melting of a vortex lattice in presence of random impurities. Impurities are introduced either through a protocol in which vortex lattice is produced in an impurity potential or first creating the vortex lattice in the absence of random pinning and then cranking up the (co-rotating) impurity potential. We find that for a fixed strength, pinning of vortices at randomly distributed impurities leads to the new states of vortex lattice. It is unearthed that the vortex lattice follow a two-step melting via loss of positional and orientational order. Also, the comparisons between the states obtained in two protocols show that the vortex lattice states are metastable states when impurities are introduced after the formation of an ordered vortex lattice. We also show the existence of metastable states which depend on the history of how the vortex lattice is created.Comment: Accepted in Euro. Phys. Let

Modulational instability in binary spin-orbit-coupled Bose-Einstein condensates

We study modulation instability (MI) of flat states in two-component spin-orbit-coupled (SOC) Bose-Einstein condensates (BECs) in the framework of coupled Gross-Pitaevskii equations for two components of the pseudospinor wave function. The analysis is performed for equal densities of the components. Effects of the interaction parameters, Rabi coupling, and SOC on the MI are investigated. In particular, the results demonstrate that the SOC strongly alters the commonly known MI (immiscibility) condition, $g_{12} > g_{1} g_{2}$, for the binary superfluid with coefficients $g_{1,2}$ and $g_{12}$ of the intra- and interspecies repulsive interactions. In fact, the binary BEC is always subject to the MI under the action of the SOC, which implies that the ground state of the system is plausibly represented by a striped phase

A Survey on Topology and Position Based Routing Protocols in Vehicular Ad hoc Network (VANET)

Vehicular Ad Hoc Networks (VANET) is a subclass of Mobile ad hoc networks. It is a developing new technology in which vehicles interchange the information from one vehicle to another vehicle within a network. VANET is responsible for providing an illustrated approach for Intelligent Transport System (ITS). The main use of VANET is to save life and prevent the accidents. This Paper describes a survey of routing protocols in vehicular ad hoc networks. The survey of routing protocols in VANET is significant and essential for smart ITS. The routing protocols are divided into two categories of topology-based and position-based routing for VANETs. This review discusses the advantages and disadvantages of these routing protocols

Stochastic R-Tuple Estimation for Unicast Routing Protocol in VANET

Vehicular Ad hoc NETwork (VANET) is a latest technology that enables vehicles to communicate with infrastructure and with vehicle. It comes under the sub class of Mobile Ad hoc NETwork (MANET). In VANET all participating nodes are highly moving. VANET has two type of communication vehicle to infrastructure (V2I) and vehicle to vehicle (V2V). Each vehicle equipped with on board unit (OBUs) that gives the service of communicating with road side unit (RSUs). Main motivation behind VANET is to provide safety from accident and avoid the accident To manage the traffic VANETs play an important role for Intelligent Transportation Systems (ITS). VANET has high mobility compare to MANET. Due to high mobility, routing is biggest challenge. In this paper, reliability tuple estimation protocol (RTEP) is proposed for unicast routing protocol in VANET. R-Tuple plays a vital role in selecting reliable route between source and target vehicle. R-Tuple has three parameter range, direction and speed of the vehicle. Reliable route is selected based on these parameters

Caffeine-Induced Global Reductions in Resting-State BOLD Connectivity Reflect Widespread Decreases in MEG Connectivity.

In resting-state functional magnetic resonance imaging (fMRI), the temporal correlation between spontaneous fluctuations of the blood oxygenation level dependent (BOLD) signal from different brain regions is used to assess functional connectivity. However, because the BOLD signal is an indirect measure of neuronal activity, its complex hemodynamic nature can complicate the interpretation of differences in connectivity that are observed across conditions or subjects. For example, prior studies have shown that caffeine leads to widespread reductions in BOLD connectivity but were not able to determine if neural or vascular factors were primarily responsible for the observed decrease. In this study, we used source-localized magnetoencephalography (MEG) in conjunction with fMRI to further examine the origins of the caffeine-induced changes in BOLD connectivity. We observed widespread and significant (p < 0.01) reductions in both MEG and fMRI connectivity measures, suggesting that decreases in the connectivity of resting-state neuro-electric power fluctuations were primarily responsible for the observed BOLD connectivity changes. The MEG connectivity decreases were most pronounced in the beta band. By demonstrating the similarity in MEG and fMRI based connectivity changes, these results provide evidence for the neural basis of resting-state fMRI networks and further support the potential of MEG as a tool to characterize resting-state connectivity

Comparison of two insertion techniques of classic laryngeal mask airway: standard versus 90-degree rotation

Background: Laryngeal mask airway (LMA) devices have been widely utilized as an alternative to tracheal intubation in various clinical situations. The rotation technique has been suggested to improve the insertion success rate of laryngeal masks. The objective of the present study was to compare the ease of insertion of laryngeal mask in terms of, success rate at the first attempt, number of LMA insertion attempts, time duration of LMA insertion and complications like blood stain on LMA and sore throat.Methods: This prospective cohort study was conducted to compare the success rate of insertion at the first attempts between standard technique and 90 degree rotational technique at Department of Anaesthesiology, Amala institute of medical sciences, Thrissur, India during the period from March 2014-september 2015. A total of 160 patients each group consisting of 80 was included in the study after meeting inclusion criteria. Success rate of insertion at first attempts, number of insertion attempts, and insertion time of successful attempt, overall success rate, blood staining of laryngeal mask airway (LMA) and postoperative sore throat were recorded.Results: Significant difference was existed between the two groups with regard to gender. Statistically insignificant differences were observed for demographics like age, weight, ASA grades between the two study groups. Significant differences were observed among the study groups on all findings of LMA insertion. Statistically insignificant difference was detected for the time of duration of LMA insertion and change in heart rate, but mean arterial pressure was found statistically significant between the two groups.Conclusions: This study found that 90 degree rotational technique has high success rate of insertion at first attempt & is less traumatic than standard technique

Graph Sparsifications using Neural Network Assisted Monte Carlo Tree Search

Graph neural networks have been successful for machine learning, as well as for combinatorial and graph problems such as the Subgraph Isomorphism Problem and the Traveling Salesman Problem. We describe an approach for computing graph sparsifiers by combining a graph neural network and Monte Carlo Tree Search. We first train a graph neural network that takes as input a partial solution and proposes a new node to be added as output. This neural network is then used in a Monte Carlo search to compute a sparsifier. The proposed method consistently outperforms several standard approximation algorithms on different types of graphs and often finds the optimal solution.Comment: arXiv admin note: substantial text overlap with arXiv:2305.0053

Engineered exciton diffusion length enhances device efficiency in small molecule photovoltaics

n organic photovoltaic blends, there is a trade-off between exciton harvesting and charge extraction because of the short exciton diffusion length. Developing a way of increasing exciton diffusion length would overcome this trade-off by enabling efficient light harvesting from large domains. In this work, we engineered (enhanced) both exciton diffusion length and domain size using solvent vapour annealing (SVA). We show that SVA can give a three-fold enhancement in exciton diffusion coefficient (D) and nearly a doubling of exciton diffusion length. It also increases the domain size, leading to enhancement of charge extraction efficiency from 63 to 89%. Usually larger domains would reduce exciton harvesting but this is overcome by the large increase in exciton diffusion, leading to a 20% enhancement in device efficiency