Nanolithography for metallic quasi crystals for nanobio applications

There is currently an urgent need to develop micro and nanotechnique for the fabrications of quasi periodic crystals in a plane for the study and applications of novel optical properties when light propagating in or through such a photonic structures with fold symmetries (10 fold symmetry in this work). It has been clear that quasi periodical crystals in dielectrics with various fold symmetries also exhibits complete photonic band gap (PBG) property as periodical photonic crystals do. However, the novel physical properties related to the interactions of electromagnetic waves with metallic holes arrays in quasi periodical order (metallic quasi crystals) is being discovered both theoretically and experimentally, which demands technical development for the construction of theoretically designed structures. [1] In this work, we report a nanofabrication technique recently developed for the replication of quasi crystal in 100 nm Al on a slab (quartz wafer in this work) by electron beam lithography using chemically amplified resist, UVN-30. A wealth of novel photonic behaviours of lights vertically incident through the q-crystal were observed

Hall effect and resistivity in underdoped cuprates

The behaviour of the Hall ratio $R_{H}(T)$ as a function of temperature is one of the most intriguing normal state properties of cuprate superconductors. One feature of all the data is a maximum of $R_{H}(T)$ in the normal state that broadens and shifts to temperatures well above $T_c$ with decreasing doping. We show that a model of preformed pairs-bipolarons provides a selfconsistent quantitative description of $R_{H}(T)$ together with in-plane resistivity and uniform magnetic susceptibility for a wide range of doping.Comment: 4 pages, 2 figures, the model and fits were refine

The effect of different metallic counterface materials and different surface treatments on the wear and friction of polyamide 66 and its composite in rolling-sliding contact

Original article can be found at: http://www.sciencedirect.com/science/journal/00431648 Copyright Elsevier B. V. DOI: 10.1016/S0043-1648(03)00054-1The effect of different metallic counterface materials and different surface treatments on the tribological behaviour of polymer and polymer composite under unlubricated, non-conformal and rolling-sliding contact has been investigated. The most widely used polymer materials - unreinforced polyamide 66 and its composite (RFL4036) – were tested. The metallic materials include aluminium, brass and steel and the surface treatments include Tufftride** treated (known as nitrocarbonising) and magnesium phosphate treated, etc. Tests were conducted over a range of slip ratios at a fixed load of 300 N, 1000 rpm rotational speed using a twin-disc test rig. The experimental results showed that the polyamide composite exhibited less friction and wear than the unreinforced polyamide 66 when running against steel and aluminium counterfaces. However, when tested against brass, polyamide 66 exhibited lower wear than the composite. The surface treatment of steel has a significant effect on the coefficient of friction and the wear rate, as well as on the tribological mechanism, of polyamide 66 composites. It has been observed that a thin film on the contact surface plays a dominant role in reducing the wear and friction of the composite and in suppressing the transverse cracks. This study clearly indicates that both the characteristics of the different counterface metallic materials and the surface treatment greatly control the wear behaviour of polyamide 66 and its composite.Peer reviewe

Particular Solutions for Axisymmetric Helmholtz-Type Operators

In this paper, we consider the solution of the axisymmetric heat equation with axisymmetric data in an axisymmetric domain in R-3. To solve this problem, we remove the time-dependence by various transform or time-stepping methods. This converts the problem to one of a sequence of modified inhomogeneous Helmholtz equations. Generalizing previous work, we consider solving these equations by boundary-type methods. In order to do this, one needs to subtract off a particular solution, so that one obtains a sequence of modified homogeneous Helmholtz equations. We do this by modifying the usual Dual Reciprocity Method (DRM) and approximating the right-hand sides by Fourier-polynomials or bivariate polynomials. This inevitably leads to analytical solving a sequence of ordinary differential equations (ODEs.) The analytic formulas and their precision are checked using MATHEMATICA. In fact, by using an infinite precision technique, the particular solutions can be obtained with infinite precision themselves. This work will form the basis for numerical algorithms for solving axisymmetric heat equation. (C) 2005 Elsevier Ltd. All rights reserved

Lepton Flavour Violation in Unparticle Physics

Recently H. Georgi has introduced an unparticle \unpart in order to describe the low energy physics of a nontrivial scale invariant sector of an effective theory. In this work we have explored the phenomenology of an unparticle using the lepton flavour violating decay $\mu^{-}\to e^{-} e^{+} e^{-}$, and found that the branching ratio of this decay is strongly dependent on the scaling dimension.Comment: 7 pages, 3 figures; typographical errors corrected and references added in version

System-focused risk identification and assessment for disaster preparedness: Dynamic threat analysis

AbstractCurrent approaches to risk management stress the need for dynamic (i.e. continuous, ongoing) approaches to risk identification as part of a planned resource application aimed at reducing the expected consequences of undesired outcomes for the object of the assessment. We contend that these approaches place insufficient emphasis on the system knowledge available to the assessor, particularly in respect of three factors, namely the dynamic behavior of the system under threat, the role of human agents and the knowledge availability to those agents.In this paper we address the first of these shortcomings, namely the mobilization of explicit system knowledge in the identification of risks. We present a procedure for mobilizing quantitative and qualitative dynamic system knowledge using the case of flood threat to an electricity substation as a worked example. We assert that the approach described offers the potential of improving risk cognition by mobilizing system knowledge

Meso-scale transboundary units for the management of coral reefs in the South China Sea area

Local communities and local government units are recognized as the primary stakeholders and participants in the management of coral reef resources and the primary beneficiaries of small-scale fishing activities in the nearshore areas of the coastal zone. The issues relating to the management of the coastal zone are multi-faceted and some issues are largely intertwined with national policy and development goals. Thus, national governments have jurisdiction over these nearshore coastal resources to harmonize policies, monitor resource use and provide incentives for sustainable use. However, the natural boundaries of these reef resources, the processes that support reef ecosystems, and the local or national affiliation of the people who benefit from them may transcend the boundaries of the local and national management units. Therefore, efforts to arrest the decline in fish catch and loss of biodiversity for reefs require management interventions and assessment activities to be carried out at varying scales. In Southeast Asia, some aspects of reef and reef resources management — particularly in deciding the allocation of catch among competing fisheries, development of sustainable harvest strategies, use of broodstock for restocking or stock enhancement programs, protection of nursery and spawning areas, designation of systems of marine protected areas, and the identification of representative, adequate and comprehensive areas for biodiversity conservation in the region — may require the definition of larger management units. At the regional level, multi-country initiatives will need to define units for the transboundary management of resources. The use of large marine ecosystems (LMEs) to identify and manage fisheries resources may be a starting point; however, given the relatively sedentary nature of coral reef-dwelling and reef-associated organisms compared with other pelagic and demersal species, meso-scale transboundary units within the LMEs have to be defined. This paper provides suggestions for transboundary management units for coral reef and reef-associated resources in Southeast Asia based on information from genetic structures of model organisms in the region. In addition, specific reef areas are identified, which may be important beyond their national boundaries, as potential sources of recruits.Coral reefs, Resource management, Large marine ecosystems, Population genetics, Reef fisheries, Fishery management, South China Sea,

Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model

Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various $B\to P(V)T$ decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios \calB(B\to VT)/\calB(B\to PT) for some strangeness-changing processes are very sensitive to the CKM angle $\gamma$ ($\phi_3$).Comment: 23 pages, REVTEX; minor clarifications included; to appear in Phys. Rev.

Review of high voltage direct current cables

Increased renewable energy integration and international power trades have led to the construction and development of new HVDC transmission systems. HVDC cables, in particular, play an important role in undersea power transmission and offshore renewable energy integration having lower losses and higher reliability. In this paper, the current commercial feasibility of HVDC cables and the development of different types of HVDC cables and accessories are reviewed. The non-uniform electric field distribution caused by the applied voltage, temperature dependent conductivity, and space charge accumulation is briefly discussed. Current research in HVDC cable for higher operation voltage level and larger power capacity is also reviewed with specific focus on the methodologies of space charge suppression for XLPE extruded cable