AdS Black Hole with Phantom Scalar Field

In this paper, we present an AdS black hole solution with Ricci flat horizon in Einstein-phantom scalar theory. The phantom scalar fields just depend on the transverse coordinates $x$ and $y$, and which are parameterized by the parameter $\alpha$. We study the thermodynamics of the AdS phantom black hole. Although its horizon is a Ricci flat Euclidean space, we find that the thermodynamical properties of the black hole solution are qualitatively same as those of AdS Schwarzschild black hole. Namely there exists a minimal temperature, the large black hole is thermodynamically stable , while the smaller one is unstable, so there is a so-called Hawking-Page phase transition between the large black hole and the thermal gas solution in the AdS spacetime in Poincare coordinates. We also calculate the entanglement entropy for a strip geometry dual to the AdS phantom black holes and find that the behavior of the entanglement entropy is qualitatively the same as that of the black hole thermodynamical entropy.Comment: 6 pages, 8 figure

Convergence to diffusion waves for solutions of Euler equations with time-depending damping on quadrant

This paper is concerned with the asymptotic behavior of the solution to the Euler equations with time-depending damping on quadrant $(x,t)\in \mathbb{R}^+\times\mathbb{R}^+$, \begin{equation}\notag \partial_t v - \partial_x u=0, \qquad \partial_t u + \partial_x p(v) =\displaystyle -\frac{\alpha}{(1+t)^\lambda} u, \end{equation} with null-Dirichlet boundary condition or null-Neumann boundary condition on $u$. We show that the corresponding initial-boundary value problem admits a unique global smooth solution which tends time-asymptotically to the nonlinear diffusion wave. Compared with the previous work about Euler equations with constant coefficient damping, studied by Nishihara and Yang (1999, J. Differential Equations, 156, 439-458), and Jiang and Zhu (2009, Discrete Contin. Dyn. Syst., 23, 887-918), we obtain a general result when the initial perturbation belongs to the same space. In addition, our main novelty lies in the facts that the cut-off points of the convergence rates are different from our previous result about the Cauchy problem. Our proof is based on the classical energy method and the analyses of the nonlinear diffusion wave

Plasmonic Paper as a Novel Chem/Bio Detection Platform

The time varying electric field of electromagnetic (EM) radiation causes oscillation of conduction electrons of metal nanoparticles. The resonance of such oscillation, termed localized surface plasmon resonance (LSPR), falls into the visible spectral region for noble metals such as gold, silver and copper. LSPR of metal nanostructures is sensitive to numerous factors such as composition, size, shape, dielectric properties of surrounding medium, and proximity to other nanostructures (plasmon coupling). The sensitivity of LSPR to the refractive index of surrounding medium renders it an attractive platform for chemical and biological sensing. When the excitation light is in resonance with the plasmon frequency of the metal nanoparticle, it radiates a characteristic dipolar radiation causing a characteristic spatial distribution in which certain areas show higher EM field intensity, which is manifested as electromagnetic field enhancement. Surface enhanced Raman scattering (SERS) involves dramatic enhancement of the intensity of the Raman scattering from the analyte adsorbed on or in proximity to a nanostructured metal surface exhibiting such strong EM field enhancement. Both LSPR and SERS have been widely investigated for highly sensitive and label-free chemical & biological sensors. Most of the SERS/LSPR sensors demonstrated so far rely on rigid planar substrates (e.g., glass, silicon) owing to the well-established lithographic approaches, which are routinely employed for either fabrication or assembly of plasmonic nanotransducers. In many cases, their rigid nature results in low conformal contact with the sample and hence poor sample collection efficiency. We hypothesized that paper substrates are an excellent alternative to conventional rigid substrates to significantly improve the (multi-)functionality of LSPR/SERS substrates, dramatically simplify the fabrication procedures and lower the cost. The choice of paper substrates for the implementation of SERS/LSPR sensors is rationalized by numerous advantages such as (i) high specific surface area resulting in large dynamic range (ii) excellent wicking properties for rapid uptake and transport of analytes to test domains (iii) compatibility with conventional printing approaches, enabling multi-analyte plasmonic sensors (iv) significant reduction in cost (v) smaller sample volume requirement (vi) easy disposability. In this work, we have introduced novel SERS and LSPR substrates based on conventional filter paper decorated with plasmonic nanostructures, called plasmonic paper. A flexible SERS substrate based on common filter paper adsorbed with gold nanostructures allows conformal contact with real-world surfaces, enabling rapid trace detection. To realize multifunctional SERS substrates, paper substrates were cut into star-shaped structures and the fingers were differentially functionalized with polyelectrolytes that allows separation and pre-concentration of different components of a complex sample in a small surface area by taking advantage of the properties of cellulose paper and shape-enhanced capillary effect. Plasmonic paper can also serve as a novel LSPR biosensing platform by decorating the paper substrate with biofunctionalized nanostructures. Furthermore, calligraphy approach was employed to create well-isolated test domains on paper substrates using functionalized plasmonic nanostructures as ink for multiplexed chemical sensing and label-free biosensing. These plasmonic paper substrates exhibit excellent sample collection efficiency and do not require complex fabrication processes. This class of substrates is expected to have applications not only to first responders and military personal but also to several areas of medical, food analysis, and environmental research

New Optimal High Efficiency Dsp-based Digital Controller Design For Super High-speed Permanent Magnet Synchronous Motor

This dissertation investigates digital controller and switch mode power supply design for super high-speed permanent magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler that is currently under development at the University of Central Florida with support from NASA Kennedy Space Center and the Florida Solar Energy Center. Advanced motor design methods, control strategies, and rapid progress in semiconductor technology enables production of a highly efficient digital controller. However, there are still challenges for such super high-speed controller design because of its stability, high-speed, variable speed operation, and required efficiency over a wide speed range. Currently, limited research, and no commercial experimental analysis, is available concerning such motors and their control system design. The stability of a super high-speed PMSM is an important issue particularly for open-loop control, given that PMSM are unstable after exceeding a certain applied frequency. In this dissertation, the stability of super high-speed PMSM is analyzed and some design suggestions are given to maximize this parameter. For ordinary motors, the V/f control curve is a straight line with a boost voltage because the stator resistance is negligible and only has a significant effect around the DC frequency. However, for the proposed super high-speed PMSM the situation is quite different because of the motor\u27s size. The stator resistance is quite large compared with the stator reactive impedance and cannot be neglected when employing constant a V/f control method. The challenge is to design an optimal constant V/f control scheme to raise efficiency with constant V/f control. In the development, test systems and prototype boards were built and experimental results confirmed the effectiveness of the dissertation system

The role of dendritic cells (DC) in Friend retrovirus-induced immunosuppression and immunotherapeutic applications of functionalized nanoparticles

Friend murine leukemia Virus (FV) infection of immunocompetent mice is a well- established model to acquire further knowledge about viral immune suppression mechanisms, with the aim to develop therapeutics against retrovirus-induced diseases. Interestingly, BALB/c mice are infected by low doses of FV and die from FV-induced erythroleukemia, while C57/BL6 mice are infected by FV only at high viral dose, and remain persistently infected for their whole life. Due to the central role of dendritic cells (DC) in the induction of anti-viral responses, we asked for their functional role in the genotype-dependent sensitivity towards FV infection. In my PhD study I showed that bone marrow (BM)-derived DC differentiated from FV-infected BM cells obtained from FV-inoculated BALB/c (FV susceptible) and C57BL/6 (FV resistant) mice showed an increased endocytotic activity and lowered expression of MHCII and of costimulatory receptors as compared with non-infected control BMDC. FV-infected BMDC from either mouse strain were partially resistant towards stimulation-induced upregulation of MHCII and costimulators, and accordingly were poor T cell stimulators in vitro and in vivo. In addition, FV-infected BMDC displayed an altered expression profile of proinflammator cytokines and favoured Th2 polarization. Ongoing work is focussed on elucidating the functional role of proteins identified as differentially expressed in FV-infected DC in a genotype-dependent manner, which therefore may contribute to the differential course of FV infection in vivo in BALB/c versus C57BL/6 mice. So far, more than 300 proteins have been identified which are differently regulated in FV-infected vs. uninfected DC from both mouse strains. One of these proteins, S100A9, was strongly upregulated specifically in BMDC derived from FV-infected C57BL/6 BM cells. S100A9-/- mice were more sensitive towards inoculation with FV than corresponding wild type (WT) mice (both C57BL/6 background), which suggests a decisive role of this factor for anti-viral defense. In addition, FV-infected S100A9-/- BMDC showed lower motility than WT DC. The future work is aimed to further elucidate the functional importance of S100A9 for DC functions. To exploit the potential of DC for immunotherapeutic applications, in another project of this PhD study the usability of different types of functionalized nanoparticles , based on either dextran molecules or a ferromagnetic solid core, to induce potent immune responses was assessed. We tested nano-sized dextran (DEX) particles to serve as a DC-addressing nanocarrier platform. Non-functionalized DEX particles had no immunomodulatory effect on bone marrow (BM)-derived DCin vitro. However, when adsorbed with ovalbumine (OVA), DEX particles were efficiently engulfed by DC in a mannose receptor-dependent manner. A DEX-based nanovaccine containing OVA and lipopolysaccharide (LPS) as a DC stimulus induced strong OVA peptide-specific CD4+ and CD8+ T cell proliferation both in vitro and in vivo, as well as a robust OVA-specific humoral immune response (IgG1>IgG2a) in vivo. Accordingly, this nanovaccine raised a stronger induction of cytotoxic CD8+ T cells than obtained upon administration of OVA and LPS in soluble form. Therefore, DEX-based nanoparticles constitute a potent, versatile and easy to prepare nanovaccine platform for immunotherapeutic approaches. In order to enhance tumor antigen-specific immune responses by in vivo delivery of antigen and adjuvant specifically to DC, three issues were considered for the ferromagnetic solid core nanoparticle: Due to the inherent capability of CD8+DEC205+ DC to efficiently cross-present antigens and thereby prime CD8+ T cells, solid core nanoparticles (NP) were conjugated with a DEC205-specific antibody (αDEC205) In addition, NP were coated with the model antigen ovalbumin (OVA), constitutively expressed by a OVA-transduced B16 melanoma subline (B16/OVA) used for subcutaneous tumor inoculation. NPs were coupled in addition with the TLR9 ligand CpG as an adjuvant to activate DC. In vivo studies revealed superior efficacy of this trifunctional NP formulation (NP[OVA+CpG+αDEC205]) to evoke antigen-specific T cell (CD4+,CD8+) proliferation, and induction of cytotoxic T lymphocyte responses, as compared with other types of NPs (NP[OVA], NP[OVA+CpG]). Accordingly, in a therapeutic B16/OVA melanoma model, only tumor-burdened mice vaccinated with trifunctional NP showed a pronounced anti-tumor response as reflected by an arrested tumor growth and significantly higher survival rate as compared with groups of mice left untreated or vaccinated with either of the other NP formulations. Interestingly, in vivo these solid core NP were found to bind specifically to B cells due to opsonization with heat-labile serum components as confirmed by in vitro studies. Furthermore, NP that codelivered with ovalbumin (OVA) and CpG mounted OVA-specific antibody production. Additional conjugation with aDEC205 antibody, known to enhance antigen uptake by dendritic cells (DC) and subsequent induction of T cell helper cells (see above) which provide B cell activation in an antigen-specific manner, indeed enhanced OVA-specific antibody production, with a strong Th1 bias. Therefore, the efficacy of these Fe-NP for the B cell based immunotherapy was analysed. In therapeutic OVA-based anaphylaxis model, the particles conjugated with OVA and CpG inhibited significant IgE production, and the survival in the group which immunized with p(OVA-CpG) and p(OVA-CpG-aDEC205) was increased. In a model of OVA-based acute asthma, administration of NP conjugated with OVA+CpG was effective to attenuate bronchial hyper responsiveness, and inflammation of the lung was reduced. Taken together, Fe-NP nanoparticles constitute a well available nanoform most suitable for the induction of strong celluler and humoral immune responses, essential for the therapy of infectious diseases and supportive of anti-tumor.183 S

First Excursion Probabilities of Non-Linear Dynamical Systems by Importance Sampling

This paper suggests a procedure to estimate first excursion probabilities for non-linear dynamical systems subjected to Gaussian excitation. The approach is based on the mean up-crossing rate and importance sampling method. Firstly, by using of Poisson assumption and Rice formula, the equivalent linear system is carried out. The linearization principle is that non-linear and linear systems have the same up-crossing rate for a specified threshold. Secondly, an importance sampling technique is used in order to estimate excursion probabilities for the equivalent linear system. The variance of the failure probability estimates, the number of samples and the computational time are reduced significantly compared with direct Monte Carlo simulations

Assessing the Impacts of China’s Accession to the WTO

Màster Oficial d'Internacionalització, Facultat d'Economia i Empresa, Universitat de Barcelona. Curs: 2022-2023. Tutor: Dr. Marta Abegón NovellaThis paper aims to provide a comprehensive analysis of the impact of China's accession to the WTO after 22 years, from the perspective of political, economic, and social impacts. The findings of this paper demonstrate that China's accession has had a generally positive impact on its politics and economy. China's international standing has been increasing due to its growing economy. With the rapid growth in trade flow, China has experienced continuous trade surpluses. The labor-intensive manufacturing industry has experienced significant growth, particularly in electronics, textiles, and clothing. Although the automotive and agriculture industries have struggled to compete with international enterprises. However, the social impact that WTO accession has brought to the country was generally negative. Income inequality and educational attainment in China remain concerns post-accession. These findings can inform relevant policymakers and stakeholders in developing appropriate measures for the future