Refractory metals: A primer

Refractory metals have found wide-spread use in structural, electronic, chemical, and nuclear applications because they display unique physical and mechanical properties over a wide range of temperatures. Modern purification, processing, and alloying techniques have made a wide variety of refractory metals available in standard mill product form. Smaller quantities of non-typical alloys can also be made. As a whole, nearly one million tonnes of refractory metals are produced each year worldwide.     

Symptom-dependent taste aversion induced by an anticoagulant rodenticide in the brown rat (–Rattus norvegicus–R).

In a series of 3 experiments with different experimental paradigms, feeding patterns of laboratory rats (Rattus norvegicus) were monitored in 2-choice feeding tests after intubation with a sublethal dose of an anticoagulant rodenticide. The authors report for the first time that contrary to accepted wisdom, anticoagulants can induce taste aversions. Furthermore, we report behavioral symptoms within the 1st day after dosing. Our data suggest that the taste aversion is induced through an inhibition of the vitamin K cycle and is transient, attenuating over the same period as the levels of vitamin K-dependent proteins return to normal. Because the taste aversion is expressed most strongly when symptoms are most pronounced and is not expressed after symptoms have disappeared, the authors term this novel form of control symptom-dependent taste aversion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Web‐based resource model for scholarship 2.0: object reuse & exchange

Digital scholarship offers the opportunity to move beyond the limitations of traditional scholarly publication. Rather than limiting scholarly communication to text‐based static documents, the Web makes it possible for scholars to expose and share the full evidence of their research including data, images, video, and other genre of materials. These aggregations of evidence, or compound documents, can then be integrated into a linked data cloud, the basis of Scholarship 2.0—an open environment in which scholars collaborate and build new knowledge on the existing scholarship. We present Open Archives Initiative–Object Reuse and Exchange (OAI–ORE), a set of standards to identify and describe aggregations of WebResources, thereby making the Scholarship 2.0 vision possible. Copyright © 2010 John Wiley & Sons, Ltd.     

Microstructure/processing relationships in reaction-synthesized titanium aluminide intermetallic matrix composites

Near-γ TiAl- and Al₃Ti-based intermetallic matrix composites have been produced using in-situ reaction-synthesis techniques. The intermetallic matrices have been reinforced with relatively high loadings (e.g., 20 to 50 vol pct) of dispersed TiB₂ particulates. It is shown that the as-synthesized TiB₂ size is strongly dependent on the specific alloy formulation; specifically, the TiB₂ size tends to increase as the nominal volume percent of TiB₂ in the composite increases. The observed size effect is determined to be associated with the temperature that is attained during the synthesis event, which is established primarily by the net exothermicity of the participating synthesis reaction(s). The exothermicity of the reactions can be assessed through the calculation of a formulations’s adiabatic temperature, which is found to increase with the percentage of TiB₂ over the range of approximately 10 to 60 vol pct. The coupling of a composite’s characteristic adiabatic temperature with the resulting reinforcement size provides direct links among composition, processing, and mechanical performance, since the size of a reinforcing particle is influential in establishing the interparticle spacing, which, in turn, establishes the strengthening potency of the dispersed phase within the composite.     

Reducing object storage requirements in a multi-user environment

Many Smalltalk implementations store objects in a large file called a virtual image. Each user must have a copy of the virtual image to execute. Since the image can exceed a megabyte in size, considerable disk space is required to support such a system in a multi-user environment. In this paper, a method is described which can reduce storage requirements for systems which use generation scavenging as a memory reclamation technique. This method also improves the performance of the checkpoint operation and offline garbage-collection.     

Nordic Safety Climate Questionnaire (NOSACQ-50): A new tool for diagnosing occupational safety climate

Although there is a plethora of questionnaire instruments for measuring safety climate or culture, very few have proven able to present a factor structure that is consistent in different contexts, and many have a vague theoretical grounding. The Nordic Safety Climate Questionnaire (NOSACQ-50) was developed by a team of Nordic occupational safety researchers based on organizational and safety climate theory, psychological theory, previous empirical research, empirical results acquired through international studies, and a continuous development process. Safety climate is defined as workgroup members’ shared perceptions of management and workgroup safety related policies, procedures and practices. NOSACQ-50 consists of 50 items across seven dimensions, i.e. shared perceptions of: 1) management safety priority, commitment and competence; 2) management safety empowerment; and 3) management safety justice; as well as shared perceptions of 4) workers’ safety commitment; 5) workers’ safety priority and risk non-acceptance; 6) safety communication, learning, and trust in co-workers’ safety competence; and 7) workers’ trust in the efficacy of safety systems. Initial versions of the instrument were tested for validity and reliability in four separate Nordic studies using native language versions in each respective Nordic country. NOSACQ-50 was found to be a reliable instrument for measuring safety climate, and valid for predicting safety motivation, perceived safety level, and self-rated safety behavior. The validity of NOSACQ-50 was further confirmed by its ability to distinguish between organizational units through detecting significant differences in safety climate.

Relevance to industry

NOSACQ-50 will enable comparative studies of safety climate between and within companies, industries and countries. It is suitable for research purposes as well as for practical use in evaluating safety climate status, as a diagnostic tool, and in evaluating the effect of safety climate interventions.     

Exploiting multi-core nodes in peer-to-peer grids

While the majority of CPUs now sold contain multiple computing cores, current grid computing systems either ignore the multiplicity of cores, or treat them as distinct, independent machines. The latter approach ignores the resource contention present between cores in a single CPU, while the former approach fails to take advantage of significant computing power. We provide a decentralized resource management framework for exploiting multi-core nodes to run multi-threaded applications in peer-to-peer grids. We present two new load-balancing schemes that explicitly account for the resource sharing and contention of multiple cores, and propose a parameterized performance prediction model that can represent a continuum of resource sharing among cores of a CPU. We use extensive simulation to confirm that our two algorithms match jobs with computing nodes efficiently, and balance load during the lifetime of the computing jobs.     

Spoofed Identities: Virus,Spam or Scam?

Identification is becoming increasingly problematic in the halls of smoke and mirrors we call ‘cyberspace’. The identity question raises its head in the context of the origin of mass-mailing viruses and worms; the relentless avalanche of spam; electronic identity theft; Internet fraud and cybersquatters. How do we recognise and respond to email address spoofing? How should we react to the evil spammer? Why must we remain vigilant in defence of our financial details and what is our recourse in the event of identity theft and fraud? How we choose to resolve these issues could determine our future freedom of use of the Internet, and a clearer understanding should allow us to navigate safely some potentially hazardous waters ahead.     

Formation of Metal Nanoparticles Directly from Bulk Sources Using Ultrasound and Application to E‐Waste Upcycling

A method for creating nanoparticles directly from bulk metal by applying ultrasound to the surface in the presence of a two‐part surfactant system is presented. Implosive collapse of cavitation bubbles near the bulk metal surface generates powerful microjets, leading to material ejection. This liberated material is captured and stabilized by a surfactant bilayer in the form of nanoparticles. The method is characterized in detail using gold, but is also demonstrated on other metals and alloys, and is generally applicable. It is shown that nanoparticles can be produced regardless of the bulk metal form factor, and the method is extended to an environmentally important problem, the reclamation of gold from an electronic waste stream.