The Effect of Silane Coupling Agents on the Durability of Titanium Alloy Joints

An aqueous solution of γ-glycidoxypropyltrimethoxysilane (GPS) applied to titanium alloy adherends greatly improved bond durabilities compared to alloy surfaces that were only abraded and solvent cleaned, γ-aminopropyltriethoxysilane (APS) also gave improved durability but was not so effective.

Three epoxy adhesives differed considerably in their responses to the five metal pretreatments that were compared. Overall, a sodium hydroxide anodise treatment gave the highest resistance to crack growth in the wedge test.     

A Simple Bioconjugate Attachment Protocol for Use in Single Molecule Force Spectroscopy Experiments Based on Mixed Self-Assembled Monolayers

Single molecule force spectroscopy is a technique that can be used to probe the interaction force between individual biomolecular species. We focus our attention on the tip and sample coupling chemistry, which is crucial to these experiments. We utilised a novel approach of mixed self-assembled monolayers of alkanethiols in conjunction with a heterobifunctional crosslinker. The effectiveness of the protocol is demonstrated by probing the biotin-avidin interaction. We measured unbinding forces comparable to previously reported values measured at similar loading rates. Specificity tests also demonstrated a significant decrease in recognition after blocking with free avidin.     

New Orleans Levee System Performance during Hurricane Katrina: 17th Street Canal and Orleans Canal North

Centrifuge modeling of the 17th Street Canal and Orleans Canal North levees was performed in this study. During hurricane Katrina the levees on the 17th Street Canal failed, leading to breaches in the outfall canal in the city. Two mechanisms were observed in the centrifuge modeling that could cause a breach. First, a water-filled crack formed in front of the floodwall as the water in the canal rose above the top of the levee. The levees on the 17th Street Canal, which were supported on clay foundations, failed when this cracking led to a translational (sliding) failure in the clay layer commencing at the toe of the floodwall. The levees at Orleans Canal North, where failure did not occur, were also modeled to demonstrate that the model tests could successfully simulate failure and nonfailure conditions. The centrifuge model tests identified the importance of the crack formation in relation to the stability of the floodwall. These tests also confirmed that levee geometry, floodwall depth of penetration, and the underlying soil profile were all critical to the performance of the system under flood loading.     

Co-Synthesis to a Hybrid RISC/FPGA Architecture

Hybrid architectures combining conventional processors with configurable logic resources enable efficient coordination of control with datapath computation. With integration of the two components on a single device, housekeeping tasks and, optionally, loop control and data-dependent branching, can be handled by the conventional processor, while regular datapath computation occurs on the configurable hardware. This paper describes a novel approach to programming such hybrid devices that gives the programmer control over mapping of data and computation between conventional processor and configurable logic. With a simple set of pragma and intrinsic function directives, the NAPA C language provides for manual control over perhaps the most important aspect of programming such hybrid devices. Alternatively, as experience is gained about tradeoffs between the two computational resources, mapping directives may eventually be generated by an external tool. The paper further describes a research prototype compiler that targets the hybrid processor model, with a concrete implementation for the National Semiconductor NAPA1000 chip. The NAPA C compiler parses the mapping directives, performs semantic analysis, and co-synthesizes a conventional processor executable combined with a configuration bit stream for the configurable logic. Two major compiler phases, the synthesis of pipelined loops and the datapath synthesis, are described in detail.     

Two-stage Fabry-Perot filters as demultiplexers in optical FDMALANs

A high-finesse optical filter can be constructed by cascading two moderate-finesse Fabry-Perot filters of different free spectral ranges. Methods for controlling the undesirable interactions within the interfilter cavity are studied. In particular, the use of an isolator, an attenuator, or a length of fiber longer than the coherence length of the light sources used is considered. The use of a three-mirror filter, which avoids the offending cavity altogether, is also considered. The implications on the number of potential users of optical frequency-division multiple-access (FDMA), local-area networks (LANs) are also addressed     

Event content in a daily survey is differentially associated with concurrent mood.

Daily life events of 79 married men (average age 43.2 yrs) were grouped according to their life content area and according to the desirability of the event as rated by the S. Associations among event groupings and concurrently measured daily mood were examined. As in studies of major life events, some event classifications were more strongly associated with mood than were others. Specifically, desirable family-leisure events and undesirable work events were strongly related to mood. It is suggested that particular life areas deserve special attention in understanding environmental stress. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Community Transport in Sydney: A Response to Inequity and Disadvantage in Public Transport

Abstract

This paper considers the development of community transport in Sydney and possible directions for its furture. It outlines the basis on which the community transport movement has developed and argues that the conditions which have given rise to a community transport movement are likely to be exacerbated in the future.     

A high-speed silicon single-electron random access memory

A silicon random access memory using a single-electron tunnelling transistor (SETT) in the form of a multiple tunnel junction (MTJ) in a silicon nanowire has been assessed in terms of its write speed, retention time, and selectivity at an operating temperature of 4.2 K