Magnetic quadrupole doublet focusing system for high energy ions

A high energy focused ion beam microprobe using a doublet arrangement of short magnetic quadrupole lenses was used to focus 1-3 MeV protons to spot sizes of 1x1 microm2 and 1-4.5 MeV carbon and silicon ion beams to spot sizes of 1.5x1.5 microm2. The results presented clearly demonstrate that this simple doublet configuration can provide high energy microbeams for microanalysis and microfabrication applications.     

Pore segmentation of cement-based materials from backscattered electron images

A technique to segment pores from a normal backscattered electron (BSE) image of cement-based materials is presented. The upper threshold grey level for porosity is determined from the inflection point of the cumulative brightness histogram of the BSE image. This represents a critical point where a small incremental grey value will cause a sudden increase in thresholded area, a condition termed as overflow. The proposed technique was found to be more consistent and reliable than existing methods. Significantly fewer images are required to achieve a satisfactory level of statistical confidence for quantifying porosity.     

The Forgiving Graph: a distributed data structure for low stretch under adversarial attack

We consider the problem of self-healing in peer-to-peer networks that are under repeated attack by an omniscient adversary. We assume that, over a sequence of rounds, an adversary either inserts a node with arbitrary connections or deletes an arbitrary node from the network. The network responds to each such change by quick “repairs,” which consist of adding or deleting a small number of edges. These repairs essentially preserve closeness of nodes after adversarial deletions, without increasing node degrees by too much, in the following sense. At any point in the algorithm, nodes v and w whose distance would have been ? in the graph formed by considering only the adversarial insertions (not the adversarial deletions), will be at distance at most ? log n in the actual graph, where n is the total number of vertices seen so far. Similarly, at any point, a node v whose degree would have been d in the graph with adversarial insertions only, will have degree at most 3d in the actual graph. Our distributed data structure, which we call the Forgiving Graph, has low latency and bandwidth requirements. The Forgiving Graph improves on the Forgiving Tree distributed data structure from Hayes et?al. (2008) in the following ways: 1) it ensures low stretch over all pairs of nodes, while the Forgiving Tree only ensures low diameter increase; 2) it handles both node insertions and deletions, while the Forgiving Tree only handles deletions; 3) it requires only a very simple and minimal initialization phase, while the Forgiving Tree initially requires construction of a spanning tree of the network.     

Impaired Higher Order Implicit Sequence Learning on the Verbal Version of the Serial Reaction Time Task in Patients With Parkinson's Disease.

Although neuroimaging studies have strongly implicated basal ganglia involvement in implicit sequence learning, serial reaction time (SRT) studies with Parkinson's disease (PD) patients have yielded mixed results. The present research sought to examine the ability of people with PD to implicitly learn sequences with different sequential structures and to objectively assess explicit knowledge. A version of the SRT task that reduces motor demands was used to compare 19 patients with PD but not dementia and 37 matched controls. PD patients showed less implicit sequence-specific learning for both sequences and reduced response time improvement over sequential trials for the more complex sequence. A closer examination revealed that the deficit involved higher order sequential associations as well as the learning of pairwise information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multifunctional Nanochemistry: Ambient,Electroless, Template-Based Synthesis and Characterization of Segmented Bimetallic Pd/Au and Pd/Pt Nanowires as High-Performance Electrocatalysts and Nanomotors

Segmented noble-metal nanowires (NWs) represent an exciting, multifunctional, one-dimensional, structural architecture with a variety of potential applications. However, the widespread use of electrodeposition in the preparation of these systems has limited their potential to be produced on a large scale, since this protocol is costly and requires complex processes and caustic reaction media. Given the inherent limitations of electrodeposition, we report, for the first time, an ambient, surfactantless, template-based approach that is not only sustainable but also efficient for the reliable production of Pd/Pt and Pd/Au segmented NWs, possessing two spatially separated, chemically distinctive, but elementally pure, axial subunits. Our simple two-step synthetic approach allows for direct and predictable control over the relative segment lengths in these nanomaterials. Moreover, thorough structural characterization of these as-prepared samples confirms that our segmented NWs maintain high-quality, crystalline, elementally pure subunits with a well-defined interface between the constituent metals. In the context of preparing segmented NWs as multifunctional nanostructures, we demonstrate that these as-prepared NWs achieve high levels of performance when employed as both electrocatalysts and nanomotors.     

The European Landscape Convention

Adopted in Florence (Italy) on 20 October 2000, the European Landscape Convention is aimed at promoting the protection, management and planning of European landscapes and organising European cooperation on landscape issues. It is the first international treaty to be exclusively concerned with all dimensions of European landscape. It applies to the entire territory of the Parties and relates to natural, urban and peri-urban areas, whether on land, water or sea. It therefore concerns not just remarkable landscapes but also ordinary everyday landscapes and blighted areas. The Convention represents an important contribution to the implementation of the objectives of the Council of Europe: these seek to protect Europeans' quality of life and well-being, taking into account landscape, cultural and natural values. The member states of the Council of Europe signatory to the European Landscape Convention declared their concern to achieve sustainable development based on a balanced and harmonious relationship between social needs, economic activity and the environment. The cultural dimension is also of fundamental importance.     

Performance evaluation of canine-associated Bacteroidales assays in a multi-laboratory comparison study

The contribution of fecal pollution from dogs in urbanized areas can be significant and is an often underestimated problem. Microbial source tracking methods (MST) utilizing quantitative PCR of dog-associated gene sequences encoding 16S rRNA of Bacteroidales are a useful tool to estimate these contributions. However, data about the performance of available assays are scarce. The results of a multi-laboratory study testing two assays for the determination of dog-associated Bacteroidales (DogBact and BacCan-UCD) on 64 single and mixed fecal source samples created from pooled fecal samples collected in California are presented here. Standardization of qPCR data treatment lowered inter-laboratory variability of sensitivity and specificity results. Both assays exhibited 100% sensitivity. Normalization methods are presented that eliminated random and confirmed non-target responses. The combination of standardized qPCR data treatment, use of normalization via a non-target specific Bacteroidales assay (GenBac3), and application of threshold criteria improved the calculated specificity significantly for both assays. Such measures would reasonably improve MST data interpretation not only for canine-associated assays, but for all qPCR assays used in identifying and monitoring fecal pollution in the environment.     

Evaluation of heat transfer correlations for HCCI engine modeling

Combustion in HCCI engines is a controlled auto-ignition of well-mixed fuel, air and residual gas. The thermal conditions of the combustion chamber are governed by chemical kinetics strongly coupled with heat transfer from the hot gas to the walls. The heat losses have a critical effect on HCCI ignition timing and burning rate, so it is essential to understand heat transfer process in the combustion chamber in the modeling of HCCI engines. In the present paper, a comparative analysis is performed to investigate the performance of well-known heat transfer correlations in an HCCI engine. The results from the existing correlations are compared with the experimental results obtained in a single-cylinder engine. Significant differences are observed between the heat transfer results obtained by using Woschni, Assanis and Hohenberg correlations.