Finite temperature calculations for the bulk properties of strange star using a many-body approach

We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetric nuclear matter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.Comment: 21 pages, 2 tables, 12 figures Astrophys. (2011) accepte

Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease

Physical Aspects of Pseudo-Hermitian and PTPT-Symmetric Quantum Mechanics

For a non-Hermitian Hamiltonian H possessing a real spectrum, we introduce a canonical orthonormal basis in which a previously introduced unitary mapping of H to a Hermitian Hamiltonian h takes a simple form. We use this basis to construct the observables O of the quantum mechanics based on H. In particular, we introduce pseudo-Hermitian position and momentum operators and a pseudo-Hermitian quantization scheme that relates the latter to the ordinary classical position and momentum observables. These allow us to address the problem of determining the conserved probability density and the underlying classical system for pseudo-Hermitian and in particular PT-symmetric quantum systems. As a concrete example we construct the Hermitian Hamiltonian h, the physical observables O, the localized states, and the conserved probability density for the non-Hermitian PT-symmetric square well. We achieve this by employing an appropriate perturbation scheme. For this system, we conduct a comprehensive study of both the kinematical and dynamical effects of the non-Hermiticity of the Hamiltonian on various physical quantities. In particular, we show that these effects are quantum mechanical in nature and diminish in the classical limit. Our results provide an objective assessment of the physical aspects of PT-symmetric quantum mechanics and clarify its relationship with both the conventional quantum mechanics and the classical mechanics.Comment: 45 pages, 13 figures, 2 table

Making sense of business analytics : the case of two start-ups

Business analytics have enabled businesses to leverage unstructured and dispersed data in order to improve their operations and position themselves better within a highly turbulent environment. While much discussion has been focused on how businesses can move from data to insights to decision making, much less is known around how businesses actually interpret the insights provided by business analytics tools. This extended abstract proposes the use of sense-making as the theoretical lens for interpreting these insights, combined with contextual information. We will be using two case studies to further explore the applicability of our proposition

Focused Ion Beam Fabrication

Contains reports on ten research projects.U.S. Army Research Office Contract DAAL03-88-K-0108Hughes Research Laboratories FellowshipSEMATECHCharles S. Draper Laboratory Contract DL-H-261827U.S. Army Research Office Contract DAAL03-87-K-0126IBM General Technologies DivisionIBM Research Divisio

The Wireless Readiness Innovation Index: Enhancing the Effectiveness of the Public Sector in New Service Introduction

National and regional public authorities need to align their planned introduction of mobile/wireless innovation with the maturity levels of both their workforce (who will manage and maintain the new applications) and their citizens (who will use them). We draw on the experience of working with local authorities in three Mediterranean countries (Greece, Italy and Spain) to develop a method towards the effective introduction and adoption of innovative mobile services by public organizations. Specifically, we discuss the development and pilot implementation of a) the Wireless Readiness Innovation Index , a tool that aims at measuring the local authority’s and end users’ readiness towards providing and using innovative wireless services and b) the Wireless Innovation Operational Toolkit , a tool that aims at matching users’ and local authority’s readiness levels with candidate services so as to maximize the likelihood of successful introduction and sustained use

EXPLORING THE ADOPTION OF UBIQUITOUS INFORMATION SYSTEMS WITHIN THE MUSEUM CONTEXT

Wireless and mobile technologies are gradually enabling the provision of innovative information services within almost all environments. This study explores the adoption of ubiquitous museum information systems that can significantly enhance and enrich the museum visit. We draw on traditional IS adoption theories and theories from Museum Studies to develop our theoretical model which is empirically tested through a survey addressed to museum visitors (n=118). Model hypotheses are tested through Partial Least Squares modelling. The results show that Performance Expectancy and Personal Innovativeness still represent the core predictors toward the adoption of museum information systems. However, we also report on the predictive strength of two context-related factors, Invisibility and Interaction, which appear to play a particular role toward the formulation of favourable user perceptions. The paper concludes with implications on the design of museum information systems and specific suggestions for future research

Atomic scale strain relaxation in axial semiconductor III-V nanowire heterostructures

Combination of mismatched materials in semiconductor nanowire heterostructures offers a freedom of bandstructure engineering that is impossible in standard planar epitaxy. Nevertheless, the presence of strain and structural defects directly control the optoelectronic properties of these nanomaterials. Understanding with atomic accuracy how mismatched heterostructures release or accommodate strain, therefore, is highly desirable. By using atomic resolution high angle annular dark field scanning transmission electron microscopy combined with geometrical phase analyses and computer simulations, we are able to establish the relaxation mechanisms (including both elastic and plastic deformations) to release the mismatch strain in axial nanowire heterostructures. Formation of misfit dislocations, diffusion of atomic species, polarity transfer, and induced structural transformations are studied with atomic resolution at the intermediate ternary interfaces. Two nanowire heterostructure systems with promising applications (InAs/InSb and GaAs/GaSb) have been selected as key examples

Focused Ion Beam Fabrication

Contains reports on eight research projects.DARPA/Naval Electronics Systems Command (Contract MDA 903-85-C-0215)DARPA/U.S. Army Research Office (Contract DAAL03-88-K-0108)U.S. Army Research Office (Contract DAAL03-87-K-0126)Charles Stark Draper LaboratoryInternational Business Machines Corporation - Research Division, General Technologies DivisionU.S. Air ForceDARP