Deconfining Phase Transition in 2+1 D: the Georgi-Glashow Model

We analyze the finite temperature deconfining phase transition in 2+1 dimensional Georgi-Glashow model. We show explicitly that the transition is due to the restoration of the magnetic $Z_2$ symmetry and that it is in the Ising universality class. We find that neglecting effects of the charged $W$ bosons leads to incorrect predictions for the value of the critical temperature and the universality class of the transition, as well as for various correlation functions in the high temperature phase. We derive the effective action for the Polyakov loop in the high temperature phase and calculate the correlation functions of magnetic vortex operators.Comment: 26 pages, 1 figure, discussion about spatial Wilson loops added, to appear in JHE

Electric Power Allocation in a Network of Fast Charging Stations

In order to increase the penetration of electric vehicles, a network of fast charging stations that can provide drivers with a certain level of quality of service (QoS) is needed. However, given the strain that such a network can exert on the power grid, and the mobility of loads represented by electric vehicles, operating it efficiently is a challenging problem. In this paper, we examine a network of charging stations equipped with an energy storage device and propose a scheme that allocates power to them from the grid, as well as routes customers. We examine three scenarios, gradually increasing their complexity. In the first one, all stations have identical charging capabilities and energy storage devices, draw constant power from the grid and no routing decisions of customers are considered. It represents the current state of affairs and serves as a baseline for evaluating the performance of the proposed scheme. In the second scenario, power to the stations is allocated in an optimal manner from the grid and in addition a certain percentage of customers can be routed to nearby stations. In the final scenario, optimal allocation of both power from the grid and customers to stations is considered. The three scenarios are evaluated using real traffic traces corresponding to weekday rush hour from a large metropolitan area in the US. The results indicate that the proposed scheme offers substantial improvements of performance compared to the current mode of operation; namely, more customers can be served with the same amount of power, thus enabling the station operators to increase their profitability. Further, the scheme provides guarantees to customers in terms of the probability of being blocked by the closest charging station. Overall, the paper addresses key issues related to the efficient operation of a network of charging stations.Comment: Published in IEEE Journal on Selected Areas in Communications July 201

Topologically massive gravity as a Pais-Uhlenbeck oscillator

We give a detailed account of the free field spectrum and the Newtonian limit of the linearized "massive" (Pauli-Fierz), "topologically massive" (Einstein-Hilbert-Chern-Simons) gravity in 2+1 dimensions about a Minkowski spacetime. For a certain ratio of the parameters, the linearized free theory is Jordan-diagonalizable and reduces to a degenerate "Pais-Uhlenbeck" oscillator which, despite being a higher derivative theory, is ghost-free.Comment: 9 pages, no figures, RevTEX4; version 2: a new paragraph and a reference added to the Introduction, a new appendix added to review Pais-Uhlenbeck oscillators; accepted for publication in Class. Quant. Gra

Scheduling electric vehicle charging at park-and-ride facilities to flatten duck curves

In this paper, we explore present a scheduling framework for large-scale electric vehicle charging to flatten duck curves stemming from the imbalance between peak electricity demand and renewable energy production. This situation adds new constraints to power system operations and increases maintenance costs. The focus is on charging systems installed at park-and-ride facilities which are gaining popularity in metropolitan cities. The scheduling problem is modeled as an integer linear problem and various case studies are generated and solved using real-world collected data. The computational experiments show that significant savings can be achieved in reducing power system ramping requirements

Location analysis of electric vehicle charging stations for maximum capacity and coverage

Electric vehicle charging facility location is a critical component of long-term strategic planning. Integration of electric vehicles into mainstream adoption has unique characteristics as it requires a careful investigation of both electric and transportation networks. In this paper, we provide an overview of recent approaches in location analyses of electric vehicle charging infrastructures. We review approaches from classical operations research for fast and slow charging stations. Sample formulations along with case studies are presented to provide insights. We discuss that classical methods are appropriate to address the coverage of charging networks which is defined as average time or distance to reach a charging station when needed. On the other hand, calculating required capacity, defined as the individual charging resources at each node, is still an open research topic. In the final part, we present stochastic facility location theory that uses queuing and other probabilistic approaches

Effect of mentha on performance, haematological and biochemical parameters in laying hens

Effects of Mentha piperita (peppermint) extract and juice on performance and immune parameters were evaluated in laying hens. A total of 252 Babcock laying hens were allocated to seven treatments with four replications of nine hens. The control hens were fed a basal diet without supplementation. Other hens were given diets supplemented with mentha extract (ME) at 50 (50ME), 100 (100ME), and 200 (200ME) mg/kg of feed or with 50 mentha juice (50MJ), 100 (100MJ) and 200 (200MJ) mg/L that was provided in the drinking water. No significant differences were detected among treatments in bodyweight, feed intake, egg mass, egg production, eggshell breaking strength, Haugh unit, and haematological and serological parameters. The ratio of gram feed to gram egg mass (feed conversion) was significantly better in the birds that received 100ME and 200ME compared with the control hens. The yolk colour index was higher in mid trial analysis (28th day). Thus, although the ME supplementation had a positive effect on feed conversion ratio and egg yolk colour at dosage rates up to 200 mg/kg, further research is needed to establish the efficacy of this herbal product and to determine the most appropriate amount to include in diets for laying hens

Performance assessment of UK's cellular network for vehicle to grid energy trading : opportunities for 5G and beyond

The proliferation of plug-in electric vehicles (PEV) and advances in high-speed low latency communication networks redefine the relationships between electricity providers and end-users. A group of PEV owners, coordinated by an aggregator, can participate in ancillary energy markets to stabilize electricity grids and, in return, receive payments for services rendered. However, PEVs are typically parked across a dispersed region possibly with diverse signal strength and data rates. Vehicle-to-Grid (V2G) applications have tight latency (e.g., 500 ms to 2 seconds) and packet-loss requirements, hence, the supporting communication infrastructure should be carefully evaluated for real-world implementations. In this paper, we assess the performance of the internet-based 4G cellular network in the United Kingdom to evaluate these key metrics. We develop a low cost and easily deployable testbed platform to collect and analyze the latency and packet loss rate of different package sizes, transport protocols, and signal strengths. Due to the availability of hardware resources and city-wide coverage of 4G networks, a single parking lot to aggregator scenario is emulated. The results show that in most cases current 4G network can deliver packets less than 500ms which is required in fast frequency response applications in the UK. On the other hand, for more complex scenarios such as multi-aggregator to distributed clients, there is a need to use 5G and beyond to meet the latency requirements. To the best of authors' knowledge, this is the first study focusing on the field testing and assessment of an actual internet-based communication network for V2G applications

Instanton molecules at high temperature - the Georgi-Glashow model and beyond

We show that correlators of some local operators in gauge theories are sensitive to the presence of the instantons even at high temperature where the latter are bound into instanton-anti-instanton "molecules". We calculate correlation functions of such operators in the deconfined phase of the 2+1 dimensional Georgi-Glashow model and discuss analogous quantities in the chirally symmetric phase of QCD. We clarify the mechanism by which the instanton-anti-instanton molecules contribute to the anomaly of axial U(1) at high temperature.Comment: 23 pages, 4 figures, minor changes are mad