B Decays in an Asymmetric Left-Right Model

Motivated by recently observed disagreements with the SM predictions in $B$ decays, we study $b \to d, s$ transitions in an asymmetric class of $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ models, with a simple one-parameter structure of the right handed mixing matrix for the quarks, which obeys the constraints from kaon physics. We use experimental constraints on the branching ratios of $b \to s \gamma$, $b \to c e {\bar \nu}_e$, and $B_{d,s}^0 -\bar{B}^0_{d,s}$ mixing to restrict the parameters of the model: $\displaystyle {g_R}/{g_L}, M_{W_2}, M_{H^\pm}, \tan \beta$ as well as the elements of the right-handed quark mixing matrix $V^R_{CKM}$. We present a comparison with the more commonly used (manifest) left-right symmetric model. Our analysis exposes the parameters most sensitive to $b$ transitions and reveals a large parameter space where left- and right-handed quarks mix differently, opening the possibility of observing marked differences in behaviour between the standard model and the left-right model.Comment: 32 pages and 8 figure

An Authorisation Scenario for S-OGSA

The Semantic Grid initiative aims to exploit knowledge in the Grid to increase the automation, interoperability and flexibility of Grid middleware and applications. To bring a principled approach to developing Semantic Grid Systems, and to outline their core capabilities and behaviors, we have devised a reference Semantic Grid Architecture called S-OGSA. We present the implementation of an S-OGSA observant semantically-enabled Grid authorization scenario, which demonstrates two aspects: 1) the roles of different middleware components, be them semantic or non-semantic, and 2) the utility of explicit semantics for undertaking an essential activity in the Grid: resource access control

Capital requirements and business cycles with credit market imperfections

The business cycle effects of bank capital regulatory regimes are examined in a New Keynesian model with credit market imperfections and a cost channel of monetary policy. Key features of the model are that bank capital increases incentives for banks to monitor borrowers, thereby reducing the probability of default, and excess capital generates benefits in terms of reduced regulatory scrutiny. Basel I and Basel II-type regulatory regimes are defined, and the model is calibrated for a middle-income country. Simulations of supply and demand shocks show that, depending on the elasticity that relates the repayment probability to the capital-loan ratio, a Basel II-type regime may be less procyclical than a Basel I-type regime.Banks&Banking Reform,Debt Markets,Access to Finance,Economic Theory&Research,Emerging Markets

S-OGSA as a Reference Architecture for OntoGrid and for the Semantic Grid

The Grid aims to support secure, flexible and coordinated resource sharing through providing a middleware platform for advanced distributing computing. Consequently, the Grid’s infrastructural machinery aims to allow collections of any kind of resources—computing, storage, data sets, digital libraries, scientific instruments, people, etc—to easily form Virtual Organisations (VOs) that cross organisational boundaries in order to work together to solve a problem. A Grid depends on understanding the available resources, their capabilities, how to assemble them and how to best exploit them. Thus Grid middleware and the Grid applications they support thrive on the metadata that describes resources in all their forms, the VOs, the policies that drive then and so on, together with the knowledge to apply that metadata intelligently

Managing semantic Grid metadata in S-OGSA

Grid resources such as data, services, and equipment, are increasingly being annotated with descriptive metadata that facilitates their discovery and their use in the context of Virtual Organizations (VO). Making such growing body of metadata explicit and available to Grid services is key to the success of the VO paradigm. In this paper we present a model and management architecture for Semantic Bindings, i.e., firstclass Grid entities that encapsulate metadata on the Grid and make it available through predictable access patterns. The model is at the core of the S-OGSA reference architecture for the Semantic Grid

Understanding semantic aware Grid middleware for e-Science

In this paper we analyze several semantic-aware Grid middleware services used in e-Science applications. We describe them according to a common analysis framework, so as to find their commonalities and their distinguishing features. As a result of this analysis we categorize these services into three groups: information services, data access services and decision support services. We make comparisons and provide additional conclusions that are useful to understand better how these services have been developed and deployed, and how similar services would be developed in the future, mainly in the context of e-Science applications

Requirements and services for metadata management

Knowledge-intensive applications pose new challenges to metadata management, including distribution, access control, uniformity of access, and evolution in time. The authors identify general requirements for metadata management and describe a simple model and service that focuses on RDF metadata to address these requirements

Release mechanism of octadecyl rhodamine B chloride from Au nanorods by ultrafast laser pulses

We investigated the release of octadecyl rhodamine B chloride (R[subscript 18]) loaded onto cetyltrimethylammonium bromide (CTAB) coated gold nanorods (NR) by pulsed ultrafast laser excitation. R[subscript 18] intercalates into the hydrophobic CTAB bilayer on the NR surface and can exchange on and off the NR with free CTAB micelles in solution. We find that laser excitation accelerates the rate of both R[subscript 18] release from the NR and R[subscript 18] binding to the NR with increasing fluence. However, at laser fluences >220 μJ/cm[superscript 2] thermal degradation of the R[subscript 18] dominates. We also find that the concentration of CTAB, particularly around the critical micelle concentration, strongly influences the release and binding rates

Grid metadata management: requirements and architecture

Metadata annotations of grid resources can potentially be used for a number of purposes, including accurate resource allocation to jobs, discovery of services, and precise retrieval of information resources. In order to realize this potential on a large scale, various aspects of metadata must be managed. These include uniform and secure access to distributed and independently maintained metadata repositories, as well as management of metadata lifecycle. In this paper we analyze these issues and present a service-oriented architecture for metadata management, called S-OGSA, that addresses them in a systematic way

AFRP retrofit of reinforced concrete columns against impact loading

Structures can be exposed to impact loads as a result of an explosion, falling objects, projectiles and vehicle collisions. Within the increasing threat of these impact sources, it is very important to protect the columns that are the vital members of the structural systems to ensure structural and personal safety. This study focuses on the performance of axially loaded reinforced concrete members subjected to impact loading. A dropped-weight test set-up developed to perform impact tests on reinforced concrete members. The test set-up was used to perform low elevation impact tests on reinforced concrete (RC) columns that targets to simulate vehicular impact against ground floor columns of low-rise buildings. Since, there is limited information about the transverse impact performances of RC columns; the main objective of this research is to assess the vulnerability of RC columns under transverse impact loads and to enhance their performances by using Aramid Fiber Reinforced Polymer (AFRP) sheets. The scope is limited to 300 mm square columns with 3 m height in low to medium rise buildings which were found to be more vulnerable to lateral impacts according to previous research conducted by the authors, (Gurbuz et al. 2010, 2011). This research provides fundamental knowledge on the behavior of RC columns under low elevation impact loading and also generates new information on impact strengthening of vulnerable concrete columns by AFRP sheets