Estimation of human exposure to natural radionuclides using in vivo skull measurements

In a preliminary study, in vivo skull measurements and in vitro urine measurements of 210Pb and nulU have been performed to find out the individual, chronic exposure to waterborne natural radionuclides of a small group of Finnish people. For their domestic water, the studied individuals use water from drilled wells containing elevated concentrations of natural uranium and its daughter nuclides ((234,235,238)U, 222Rn, (226,228)Ra, 210Po, 210Pb). Enhanced 210Pb and 235U activities were observed in several people. A positive correlation is observed between the U concentration in urine (microg d(-1)) and the number of counts (cpm) in the gamma ray energy peaks originating from the decay of 235U and 234Th respectively. Calibration of the detector set-up and the determination of background sources are in progress.     

Stable tracer investigations in humans for assessing the biokinetics of ruthenium and zirconium radionuclides

The interest in the biokinetics of ruthenium and zirconium in humans is justified by the potential radiological risk represented by their radionuclides. Only a few data related to the biokinetics of ruthenium and zirconium in humans are available and, accordingly, the biokinetic models currently recommended by the ICRP for these elements are mainly based on data from animal experiments. The use of stable isotopes as tracers, coupled with a proper analytical technique (nuclear activation analysis with protons) for their determination in biological samples, represents an ethically acceptable methodology for biokinetic investigations, being free from any radiation risk for the volunteer subjects. In this work, the results obtained in eight biokinetic investigations for ruthenium, conducted on a total of three healthy volunteers, and six for zirconium, performed on a total of three subjects, are presented and compared to the predictions of the ICRP models.     

V2O5 nanofibre sheet actuators

Vanadium oxides, such as V2O5, are promising for lithium-ion batteries, catalysis, electrochromic devices and sensors. Vanadium oxides were proposed more than a decade ago for another redox-dependent application: the direct conversion of electrical energy to mechanical energy in actuators (artificial muscles). Although related conducting polymer and carbon nanotube actuators have been demonstrated, electromechanical actuators based on vanadium oxides have not be realized. V2O5 nanofibres and nanotubes provide the potential advantages of low-cost synthesis by sol-gel routes and high charging capacity and long cycle life. Here, we demonstrate electromechanical actuation for obtained high modulus V2O5 sheets comprising entangled V2O5 nanofibres. The high surface area of these V2O5 sheets facilitates electrochemical charge injection and intercalation that causes the electromechanical actuation. We show that the V2O5 sheets provide high Young's modulus, high actuator-generated stress, and high actuator stroke at low applied voltage.     

NoSQ: Store-Load Communication without a Store Queue

The NoSQ microarchitecture performs store-load communication without a store queue and without executing stores in the out-of-order engine. It uses speculative memory bypassing for all in-flight store-load communication, enabled by a 99.8 percent accurate store-load communication predictor. The result is a simple, fast core data path containing no dedicated store-load forwarding structures     

Mechanistic modelling of 5-axis milling using an adaptive and local depth buffer

A mechanistic model for 5-axis surface machining with a toroidal-end mill is presented in this work. A graphical representation of the tool movements is used to determine the in-process chip geometry and tool edge contact length using an adaptive and local depth buffer. The graphical representation of the tool movements is generated using either tooth swept sectors that model the tool’s cutting teeth as they rotate or the swept surface of the tool as it moves along the tool path. The mechanistic model was verified with two cutting experiments: The first cutting test showed that the data agrees with the simulation results within 7% of the peak-to-peak forces. The second cutting test modelled a more complex stock surface and tool path. The simulation results were within 10% of the measured peak-to-peak cutting torque.     

Effects of DC Current on the Mechanical Behavior of AlMg1SiCu

The effect of an electron wind on the mechanical properties of aluminum is investigated with the ultimate goal of establishing a technique by which the mechanical energy associated with the deformation of a material can be reduced without requiring a significant increase in the material's temperature. In the study presented herein, the effect that the electrical flow has on the mechanical properties of aluminum is examined through tensile testing. However, as electricity is passed through the material, some incidental resistive heating occurs. Therefore, in order to isolate the effect of the electrical flow from that resulting from resistive heat, the effect of transient temperatures on the stress-strain behavior of aluminum is also considered, with, and without, the presence of the electrical flow. In addition, variation in the electrical effect, with respect to the aluminum's temper and electrical pre-treating, is investigated. The experimental results indicate that the electrical current has the potential to substantially reduce deformation energies without causing significant increases in the workpiece temperature. The data also indicates that this effect exists regardless of the temper on the material. Finally, the study found that electrically pre-treating the aluminum produced results similar to that of an annealing process (i.e., the energies were significantly reduced).     

Robust dimensions of anxiety sensitivity: Development and initial validation of the Anxiety Sensitivity Index-3.

Accumulating evidence suggests that anxiety sensitivity (fear of arousal-related sensations) plays an important role in many clinical conditions, particularly anxiety disorders. Research has increasingly focused on how the basic dimensions of anxiety sensitivity are related to various forms of psychopathology. Such work has been hampered because the original measure--the Anxiety Sensitivity Index (ASI)--was not designed to be multidimensional. Subsequently developed multidimensional measures have unstable factor structures or measure only a subset of the most widely replicated factors. Therefore, the authors developed, via factor analysis of responses from U.S. and Canadian nonclinical participants (n = 2,361), an 18-item measure, the ASI-3, which assesses the 3 factors best replicated in previous research: Physical, Cognitive, and Social Concerns. Factorial validity of the ASI-3 was supported by confirmatory factor analyses of 6 replication samples, including nonclinical samples from the United States and Canada, France, Mexico, the Netherlands, and Spain (n = 4,494) and a clinical sample from the United States and Canada (n = 390). The ASI-3 displayed generally good performance on other indices of reliability and validity, along with evidence of improved psychometric properties over the original ASI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constrained Information Combining: Theory and Applications for LDPC Coded Systems

This paper tightens previous information combining bounds on the performance of iterative decoding of binary low-density parity-check (LDPC) codes over binary-input symmetric-output channels by tracking the probability of erroneous bit in conjunction with mutual information. Evaluation of the new bounds as well as of other known bounds on different LDPC ensembles demonstrates sensitivity of the finite dimensional iterative bounds to lambda₂, the fraction of edges connected to degree 2 variable nodes