On signalling over through-silicon via (TSV) interconnects in 3-D integrated circuits.

This paper discusses signal integrity (SI) issues and signalling techniques for Through Silicon Via (TSV) interconnects in 3-D Integrated Circuits (ICs). Field-solver extracted parasitics of TSVs have been employed in Spice simulations to investigate the effect of each parasitic component on performance metrics such as delay and crosstalk and identify a reduced-order electrical model that captures all relevant effects. We show that in dense TSV structures voltage-mode (VM) signalling does not lend itself to achieving high data-rates, and that current-mode (CM) signalling is more effective for high throughput signalling as well as jitter reduction. Data rates, energy consumption and coupled noise for the different signalling modes are extracted

Challenges in Extracting Charged Current Quasi-Elastic Model Information in MiniBooNE's Anti-Neutrino Data

Using a high-statistics sample of anti-neutrino charged current quasi-elastic (CCQE) events, MiniBooNE reports the challenges in measuring parameters within the Relativistic Fermi Gas model. As the CCQE analysis has been completed in MiniBooNE's neutrino data, particular attention is paid to the differences in CCQE interactions between the two running modes.Comment: NuInt '09 conference proceedings. Four pages, five figure

Nanowire terahertz quantum cascade lasers

International audienceQuantum cascade lasers made of nanowire axial heterostructures are proposed. The dissipative quantum dynamics of their carriers is theoretically investigated using non-equilibrium Green functions. Their transport and gain properties are calculated for varying nanowire thickness, from the classical-wire regime to the quantum-wire regime. Our calculation shows that the lateral quantum confinement provided by the nanowires allows an increase of the maximum operation temperature and a strong reduction of the current density threshold compared to conventional terahertz quantum cascade laser

Multiple Sclerosis: Are Protective Immune Mechanisms Compromised by a Complex Infectious Background?

The immunological background of multiple sclerosis (MS) manifests as an altered reactivity against a diverse range of infections, particularly with the Epstein-Barr virus. Although this could be only an epiphenomenon of a more generalised dysfunction of the immune system in MS, it is also possible that a complex infectious background forms the basis of a specific immune dysregulation finally causing the disease. It is thus suggested that the complex infectious background bears the key for an understanding of the immune pathogenesis of the disease. It appears probable that improved standards of hygiene cause regulatory defects in the immune system, allowing the abnormal expression of human endogenous retroviral (HERV) genes. On the basis of epidemiological observations we describe how a failure of expansion or an eclipse of a subfraction of self-antigen-specific CD8+ T cells mediating immune repair, and a deleterious mode of action of HERV gene products, could underlie the pathogenesis of MS

Optical characterization of semiconductor saturable absorbers

Semiconductor saturable absorber mirror (SESAM) devices have become a key component of ultrafast passive mode-locked laser sources. Here we describe in more detail how the key SESAM parameters such as saturation fluence, modulation depth, and nonsaturable losses are measured with a high accuracy. These parameters need to be known and controlled to obtain stable pulse generation for a given laser. A high-precision, wide dynamic range setup is required to measure this nonlinear reflectivity of saturable absorbers. The challenge to measure a low modulation depth and key measures necessary to obtain an accurate calibration are described in detail. The model function for the nonlinear reflectivity is based on a simple two-level travelling wave system. We include spatial beam profiles, nonsaturable losses and higher-order absorption, such as two-photon absorption and other induced absorption. Guidelines to extract the key parameters from the measured data are give

Servant as leader : critical requirements for the appointment and training of retirement fund trustees

Abstract: The South African retirement fund industry ranks among the 15 largest retirement fund industries internationally, with some 8 million members and assets under management of close to R2 trillion. However, to be successful, retirement funds need good governance. Research purpose: To explore the most critical servant leadership qualities required that can serve as profile in the selection, appointment and training of retirement fund trustees (RFTs) to serve on boards of trustees of retirement funds in the South African context. Motivation for the study: The South African National Treasury’s retirement reform proposal clearly articulates government’s concern for the poor governance of retirement fund assets by appointed boards of trustees and the broader implications on social and economic security in retirement. It promotes the regulation of standards relating to the minimum qualifications and expertise needed to be appointed to serve on a board of trustees (BoTs). Although the measures proposed by government to improve fund governance and the role of the RFTs are sound in principle, it does not inform the character, leadership qualities or leadership competence desired for RFTs, thus leaving the management of funds in the hands of people who must make investment decisions when they themselves are not fully committed..

Parameters affecting ion intensities in transmission-mode Direct Analysis in Real-Time mass spectrometry

A survey of the effect of temperature, transmission module material and analysis time on ion intensities in transmission mode direct analysis in real time mass spectrometry is presented. Ion intensity profiles obtained for two related compounds are similar when analysed separately but are very different when analysed as a mixture