Supporting 'design for reuse' with modular design

Engineering design reuse refers to the utilization of any knowledge gained from the design activity to support future design. As such, engineering design reuse approaches are concerned with the support, exploration, and enhancement of design knowledge prior, during, and after a design activity. Modular design is a product structuring principle whereby products are developed with distinct modules for rapid product development, efficient upgrades, and possible reuse (of the physical modules). The benefits of modular design center on a greater capacity for structuring component parts to better manage the relation between market requirements and the designed product. This study explores the capabilities of modular design principles to provide improved support for the engineering design reuse concept. The correlations between modular design and 'reuse' are highlighted, with the aim of identifying its potential to aid the little-supported process of design for reuse. In fulfilment of this objective the authors not only identify the requirements of design for reuse, but also propose how modular design principles can be extended to support design for reuse

Muon spin relaxation study of the magnetism in unilluminated Prussian Blue analogue photomagnets

We present longitudinal field muon spin relaxation ($\mu$SR) measurements in the unilluminated state of the photo-sensitive molecular magnetic Co-Fe Prussian blue analogues M$_{1-2x}$Co$_{1+x}$[Fe(CN)$_6$]$\cdot z$ H$_2$O, where M=K and Rb with $x=0.4$ and $\simeq 0.17$, respectively. These results are compared to those obtained in the $x=0.5$ stoichiometric limit, Co$_{1.5}$[Fe(CN)$_6$]$\cdot 6$ H$_2$O, which is not photo-sensitive. We find evidence for correlation between the range of magnetic ordering and the value of $x$ in the unilluminated state which can be explained using a site percolation model.Comment: 7 pages, 12 figure

Analysis of common attacks in LDPCC-based public-key cryptosystems

We analyze the security and reliability of a recently proposed class of public-key cryptosystems against attacks by unauthorized parties who have acquired partial knowledge of one or more of the private key components and/or of the plaintext. Phase diagrams are presented, showing critical partial knowledge levels required for unauthorized decryptionComment: 14 pages, 6 figure

Phase II study of CC-486 (oral azacitidine) in previously treated patients with locally advanced or metastatic nasopharyngeal carcinoma

BACKGROUND: Treatment options are limited for recurrent nasopharyngeal carcinoma (NPC). We report results from a phase II study of CC-486 (oral azacitidine) in advanced NPC. PATIENTS AND METHODS: Patients with locally advanced or metastatic NPC and 1-2 prior treatment regimens received CC-486 300 mg daily on days 1-14 of 21-day cycles until disease progression or unacceptable toxicity. The first 6 patients of Asian-Pacific Islander (API) ethnicity received a reduced dose of 200 mg to preserve safety and tolerability; if well tolerated, subsequent API patients received CC-486 300 mg. The study could advance to stage 2 if > 4 patients achieved a response. Co-primary end-points were overall response rate (ORR) and progression-free survival (independent review). Key secondary end-points were overall survival and safety. RESULTS: Owing to faster-than-anticipated enrolment, 36 patients, including 13 of API ethnicity, were enrolled; the median age was 54.0 years. Most patients were male (81%) and had an Eastern Cooperative Oncology Group performance status 64 1 (97%). Among 25 efficacy-evaluable patients, the ORR was 12%; the median progression-free and overall survival were 4.7 and 18.0 months, respectively. The most common grade III/IV treatment-emergent adverse events were neutropenia (33%) and febrile neutropenia (11%). Twenty-one posttreatment deaths, primarily due to progressive disease or disease complications, and 1 on-treatment death (epistaxis, unrelated to study drug) occurred. The study did not advance to stage 2. CONCLUSION: CC-486 did not show sufficient clinical activity to support further development as monotherapy in this patient population. The safety profile of CC-486 in NPC was consistent with that in other solid tumours

Network patterns and strength of orbital currents in layered cuprates

In a frame of the $t-J-G$ model we derive the microscopical expression for the circulating orbital currents in layered cuprates using the anomalous correlation functions. In agreement with $\mu$-on spin relaxation ($\mu$SR), nuclear quadrupolar resonance (NQR) and inelastic neutron scattering(INS) experiments in YBa$_2$Cu$_3$O$_{6+x}$ we successfully explain the order of magnitude and the monotonous increase of the {\it internal} magnetic fields resulting from these currents upon cooling. However, the jump in the intensity of the magnetic fields at T$_c$ reported recently seems to indicate a non-mean-field feature in the coexistence of current and superconducting states and the deviation of the extended charge density wave vector instability from its commensurate value {\bf Q}$\approx(\pi,\pi$) in accordance with the reported topology of the Fermi surface

Andreev Bound States at the Interface of Antiferromagnets and d-wave Superconductors

We set up a simple transfer matrix formalism to study the existence of bound states at interfaces and in junctions between antiferromagnets and d-wave superconductors. The well-studied zero energy mode at the {110} interface between an insulator and a d-wave superconductor is spin split when the insulator is an antiferromagnet. This has as a consequence that any competing interface induced superconducting order parameter that breaks the time reversal symmetry needs to exceed a critical value before a charge current is induced along the interface.Comment: 4 pages, 3 figure

Thermodynamic properties of the d-density wave order in cuprates

We solve a popular effective Hamiltonian of competing $d$-density wave and d-wave superconductivity orders self-consistently at the mean-field level for a wide range of doping and temperature. The theory predicts a temperature dependence of the $d$-density wave order parameter seemingly inconsistent with the neutron scattering and $\mu$SR experiments of the cuprates. We further calculate thermodynamic quantities, such as chemical potential, entropy and specific heat. Their distinct features can be used to test the existence of the $d$-density wave order in cuprates.Comment: changed to 4 pages and 4 figures. More reference added. Accepted by Phys. Rev.

Temperature dependence of Vortex Charges in High Temperature Superconductors

Using a model Hamiltonian with d-wave superconductivity and competing antiferromagnetic (AF) interactions, the temperature (T) dependence of the vortex charge in high T_c superconductors is investigated by numerically solving the Bogoliubov-de Gennes equations. The strength of the induced AF order inside the vortex core is T dependent. The vortex charge could be negative when the AF order with sufficient strength is present at low temperatures. At higher temperatures, the AF order may be completely suppressed and the vortex charge becomes positive. A first order like transition in the T dependent vortex charge is seen near the critical temperature T_{AF}. For underdoped sample, the spatial profiles of the induced spin-density wave and charge-density wave orders could have stripe like structures at T < T_s, and change to two-dimensional isotropic ones at T > T_s. As a result, a vortex charge discontinuity occurs at T_s.Comment: 5 pages, 5 figure

Radio emission and jets from microquasars

To some extent, all Galactic binary systems hosting a compact object are potential `microquasars', so much as all galactic nuclei may have been quasars, once upon a time. The necessary ingredients for a compact object of stellar mass to qualify as a microquasar seem to be: accretion, rotation and magnetic field. The presence of a black hole may help, but is not strictly required, since neutron star X-ray binaries and dwarf novae can be powerful jet sources as well. The above issues are broadly discussed throughout this Chapter, with a a rather trivial question in mind: why do we care? In other words: are jets a negligible phenomenon in terms of accretion power, or do they contribute significantly to dissipating gravitational potential energy? How do they influence their surroundings? The latter point is especially relevant in a broader context, as there is mounting evidence that outflows powered by super-massive black holes in external galaxies may play a crucial role in regulating the evolution of cosmic structures. Microquasars can also be thought of as a form of quasars for the impatient: what makes them appealing, despite their low number statistics with respect to quasars, are the fast variability time-scales. In the first approximation, the physics of the jet-accretion coupling in the innermost regions should be set by the mass/size of the accretor: stellar mass objects vary on 10^5-10^8 times shorter time-scales, making it possible to study variable accretion modes and related ejection phenomena over average Ph.D. time-scales. [Abridged]Comment: 28 pages, 13 figures, To appear in Belloni, T. (ed.): The Jet Paradigm - From Microquasars to Quasars, Lect. Notes Phys. 794 (2009

A New Relativistic High Temperature Bose-Einstein Condensation

We discuss the properties of an ideal relativistic gas of events possessing Bose-Einstein statistics. We find that the mass spectrum of such a system is bounded by $\mu \leq m\leq 2M/\mu _K,$ where $\mu$ is the usual chemical potential, $M$ is an intrinsic dimensional scale parameter for the motion of an event in space-time, and $\mu _K$ is an additional mass potential of the ensemble. For the system including both particles and antiparticles, with nonzero chemical potential $\mu ,$ the mass spectrum is shown to be bounded by $|\mu |\leq m\leq 2M/\mu _K,$ and a special type of high-temperature Bose-Einstein condensation can occur. We study this Bose-Einstein condensation, and show that it corresponds to a phase transition from the sector of continuous relativistic mass distributions to a sector in which the boson mass distribution becomes sharp at a definite mass $M/\mu _K.$ This phenomenon provides a mechanism for the mass distribution of the particles to be sharp at some definite value.Comment: Latex, 22 page