Polytechnic University of Catalonia

About: Polytechnic University of Catalonia is a education organization based out in Barcelona, Spain. It is known for research contribution in the topics: Finite element method & Population. The organization has 16006 authors who have published 45325 publications receiving 949306 citations. The organization is also known as: UPC - BarcelonaTECH & Technical University of Catalonia.

Transparent polymer solar cells employing a layered light-trapping architecture

Abstract: Transparent polymer solar cells are demonstrated that can transmit 30% of visible light and operate with a power conversion efficiency of 5.6%. The cells employ photonic crystals to trap ultraviolet and infrared light.

Palladium sorption on glutaraldehyde-crosslinked chitosan

Abstract: The high nitrogen content of chitosan is the main reason for its ability to sorb metal ions through several mechanisms including ion-exchange or chelation, depending on the metal and the pH of the solution. Glutaraldehyde is used to crosslink chitosan through imine linkage between amine groups of chitosan and aldehyde groups of the crosslinking agent. This modified biosorbent was studied for palladium recovery in acidic medium (around pH 2). The influence of several parameters such as pH and competitor anions were studied with respect to sorption equilibrium. Sorption isotherms were obtained and modeled using the Langmuir and the Freundlich model. This study also examines the effect of palladium concentration, particle size, sorbent dosage, and the extent of crosslinking on sorption kinetics. Kinetic curves are modeled using single diffusion model equations to evaluate the predominance of either external or intraparticle mass transfer resistance. The influence of the acid used to control the pH of the solution was examined in conjunction with the influence of competitor anions. Sulfuric acid proves to be unfavorable to palladium sorption, in comparison with hydrochloric acid. However, the addition of chloride anions in a palladium solution, whose pH is controlled with sulfuric acid, enhances metal anion sorption: results are interpreted with reference to chloropalladate speciation.

Hardware support for WCET analysis of hard real-time multicore systems

Abstract: The increasing demand for new functionalities in current and future hard real-time embedded systems like automotive, avionics and space industries is driving an increase in the performance required in embedded processors. Multicore processors represent a good design solution for such systems due to their high performance, low cost and power consumption characteristics. However, hard real-time embedded systems require time analyzability and current multicore processors are less analyzable than single-core processors due to the interferences between different tasks when accessing shared hardware resources. In this paper we propose a multicore architecture with shared resources that allows the execution of applications with hard real-time and non hard real-time constraints at the same time, providing time analizability for the hard real-time tasks so that they can meet their deadlines. Moreover our architecture proposal provides high-performance for the non hard real-time tasks.

Frontiers in multidimensional self-trapping of nonlinear fields and matter

Abstract: 2D and 3D solitons and related states, such as quantum droplets, can appear in optical systems, atomic Bose–Einstein condensates (BECs) and liquid crystals, among other physical settings. However, multidimensional solitary states supported by the standard cubic nonlinearity tend to be strongly unstable — a property far less present in 1D systems. Thus, the central challenge is to stabilize multidimensional states, and to that end numerous approaches have been proposed over the years. Most strategies involve non-cubic nonlinearities or using various potentials, including periodic ones. Completely new directions have recently emerged in two-component BECs with spin–orbit coupling, which have been predicted to support stable 2D and metastable 3D solitons. A recent breakthrough is the creation of 3D quantum droplets. These are self-sustained states existing in two-component BECs, stabilized by the quantum fluctuations around the underlying mean-field states. Here, we review recent results in this field and outline outstanding current challenges. Multidimensional self-trapped states exist in many models of physical systems. However, they are highly unstable in media with the universal cubic nonlinearity. We review different mechanisms that may stabilize them, including non-Kerr nonlinearities, spin–orbit coupling and quantum fluctuations, among others.

The LDBC Social Network Benchmark: Interactive Workload

Abstract: The Linked Data Benchmark Council (LDBC) is now two years underway and has gathered strong industrial participation for its mission to establish benchmarks, and benchmarking practices for evaluating graph data management systems. The LDBC introduced a new choke-point driven methodology for developing benchmark workloads, which combines user input with input from expert systems architects, which we outline. This paper describes the LDBC Social Network Benchmark (SNB), and presents database benchmarking innovation in terms of graph query functionality tested, correlated graph generation techniques, as well as a scalable benchmark driver on a workload with complex graph dependencies. SNB has three query workloads under development: Interactive, Business Intelligence, and Graph Algorithms. We describe the SNB Interactive Workload in detail and illustrate the workload with some early results, as well as the goals for the two other workloads.