1,266 research outputs found
Corrections to holographic entanglement plateau
We investigate the robustness of the Araki-Lieb inequality in a
two-dimensional (2D) conformal field theory (CFT) on torus. The inequality
requires that is nonnegative, where
is the thermal entropy and , are the entanglement
entropies. Holographically there is an entanglement plateau in the BTZ black
hole background, which means that there exists a critical length such that when
the inequality saturates . In thermal AdS
background, the holographic entanglement entropy leads to for
arbitrary . We compute the next-to-leading order contributions to in the large central charge CFT at both high and low temperatures. In both
cases we show that is strictly positive except for or
. This turns out to be true for any 2D CFT. In calculating the single
interval entanglement entropy in a thermal state, we develop new techniques to
simplify the computation. At a high temperature, we ignore the finite size
correction such that the problem is related to the entanglement entropy of
double intervals on a complex plane. As a result, we show that the leading
contribution from a primary module takes a universal form. At a low
temperature, we show that the leading thermal correction to the entanglement
entropy from a primary module does not take a universal form, depending on the
details of the theory.Comment: 32 pages, 8 figures; V2, typos corrected, published versio
The impact of China’s WTO accession (2001) on Hong Kong’s trade development
Mà ster Oficial d'Història Econòmica, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2020-2021, Tutor: Anna CarrerasThis paper sought to analyze the impact of China’s accession to WTO (2001) on Hong Kong's trade development. Hong Kong, as a main financial center in Asia, also an important international port, plays an important role in the world economy and global trade market. Hong Kong achieved rapid trade expansion during the 1970s-1990s and remained the stable increase trend till today. As a bridge of communication and information exchange between overseas markets and Mainland China, Hong Kong gained numerous economic benefits through imports and exports trade, also promotes the economic expansion in Mainland China. Since China's entry into WTO, Mainland China obtains a noticeable trade increase and affects Hong Kong’s commercial trade in a certain way.
To test the impact of China’s accession to WTO (2001) on trade development in Hong Kong during 1970 to 2019, I argue that China’s accession to WTO (2001) created a higher trade diversion in Hong Kong than trade creation; China’s entry in WTO affects the shift of Hong Kong’s total export composition: increasing its re-exports at the expense of domestic exports
Thermodynamic analysis of a dual-loop organic Rankine cycle (ORC) for waste heat recovery of a petrol engine
Huge amounts of low-grade heat energy are discharged to the environment by vehicular engines. Considering the large number of vehicles in the world, such waste energy has a great impact on our environment globally. The Organic Rankine Cycle (ORC), which uses an organic fluid with a low boiling point as the working medium, is considered to be the most promising technology to recover energy from low-grade waste heat. In this study, a dual-loop ORC is presented to simultaneously recover energy from both the exhaust gases and the coolant of a petrol engine. A high-temperature (HT) ORC loop is used to recover heat from the exhaust gases, while a low-temperature (LT) ORC loop is used to recover heat from the coolant and the condensation heat of the HT loop. Figure 1 shows the schematic of the dual-loop ORC. Differing from previous research, two more environmentally friendly working fluids are used, and the corresponding optimisation is conducted. First, the system structure and operating principle are described. Then, a mathematical model of the designed dual-loop ORC is established. Next, the performance of the dual-loop cycle is analysed over the entire engine operating region. Furthermore, the states of each point along the cycle and the heat load of each component are compared with the results of previous research. The results show that the dual-loop ORC can effectively recover the waste heat from the petrol engine, and that the effective thermal efficiency can be improved by about 20 ~ 24%, 14~20%, and 30% in the high-speed, medium-speed, and low-speed operation regions, respectively. The designed dual-loop ORC can achieve a higher system efficiency than previous ORCs of this structure. Therefore, it is a good choice for waste heat recovery from vehicle engines
A Computational Cognitive Model of User Applying Creativity Technique in Creativity Support Systems
AbstractNumerous creativity techniques have been purposed and applied in creativity support system. Because most creativity techniques are used informally and hardly represented formally in computer, it becomes very difficult to build the computational cognitive model of user applying those techniques. However the model is necessary for creativity support systems to detect or predict the change of user's cognitive state in time and make some adaption to avoid inhibiting creativity of user. In this paper we introduce extension creative idea generation method which has the characteristics of formalization and systematization. The method can be represented by extension rules which provide the precondition to build computational cognitive model of user in creativity support systems. The computational cognitive model of user learning in applying extension creative idea generation method is presented through experiments. The experimental results show how and when the user will develop the application skill of creativity technique and inhibit his creativity
Optimal Sizing of a Grid Independent Renewable Heating System for Building Decarbonisation
As the use of fossil fuels has led to global climate change due to global warming, most countries are aiming to reduce greenhouse gas emissions through the application of renewable energies. Due to the distributed and seasonal heating demand, the decarbonisation of heating is more challenging, especially for countries that are cold in winters. Electrically powered heat pumps are considered as an attractive solution for decarbonising heating sector. Since grid-powered heat pumps may significantly increase the power demand of the grid, this paper considers using local renewable energy to provide power for heat pumps, which is known as the grid independent renewable heating system including photovoltaic, wind turbine, battery storage system and thermal energy storage. This paper investigates a complete renewable heating system (RHS) framework and sizing the components to decarbonise building heating. The relationship between the reduction of gas consumption and the requirement of battery storage system (BSS) under the corresponding installation capacity of renewable components is analysed with their technical requirements. Then, according to different investment plans, this paper uses the particle swarm optimisation algorithm for optimal sizing of each component in the RHS to find a solution to minimise CO2 emissions. The results verify that the RHS with optimal sizing can minimise CO2 emissions and reduce the operational cost of natural gas. This work provides a feasible solution of how to invest the RHS to replace the existing heating system based on gas boilers and CHPs
Rise through coping with service failures in tourism
Service failure, a common stressor experienced by tourists during their travels, can have a far-reaching impact beyond the travel domain. This research investigates how tourists cope with service failure during their travels and its influence on their ability to rise through challenges and achieve personal growth. Through semi-structured interviews and four scenario-based experiments, we found that problem-focused coping generates a stronger sense of pride and a weaker sense of shame compared to emotion-focused strategies, fostering self-confidence and personal growth in tourists. Additionally, supportive companion reactions reinforce the positive effects of problem-focused coping, while non-supportive reactions may weaken it. The findings offer important theoretical insights, with implications for the tourism industry to develop effective recovery strategies and provide meaningful travel experiences
High Performance Low Temperature Solid Oxide Fuel Cells with Novel Electrode Architecture
In this study, we have fabricated high performance low temperature solid oxide fuel cells (LT-SOFCs) with both acicular anodes and cathodes with thin Gd-doped ceria (GDC) electrolyte film. The acicular Ni-Gd0.1Ce0.9O2−δ (Ni-GDC) anode was prepared using freeze drying tape casting, while the hierarchically porous cathode with nano-size Sm0.5Sr0.5CoO3 (SSC) particles covering an acicular GDC skeleton was prepared by a combination of freeze drying tape casting and self-rising approaches. The acicular electrodes with 5–200 μm pores/channels enhance mass transport, while SSC particles of about 50 nm in the cathode promote electrochemical reactions. Cells which have this novel electrode architecture show a significantly high power output of 1.44 W cm−2 and an extremely low cell polarization resistance of 0.0379 Ω cm2 at 600 °C
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