Morphology and structure of bainite plates in the β’ phase of an Ag-45 at. pct Cd alloy

The morphology and structure of bainite plates which formed in the ordered bcc β’ phase of a Ag-45 at. pct Cd alloy at temperatures 160 to 300°C were studied by X-ray diffraction and transmission electron microscopy. Initially, the plates formed with a 3R stacking fault modulation of the fcc structure and contained a high density of random stacking faults. The stacking faults annealed out during a prolonged isothermal treatment, the structure gradually changing to a regular fcc. The orientation relationship between the bcc matrix and the fcc bainite was as follows: [1•11]_b 0.7 deg from [0•11]_f, [110]_b 1.1 deg from [l00]_f and [011]_b 4.3 deg from the stacking fault plane pole [111]_f. The habit plane of the bainite plates, determined by two surface trace analysis, was close to (3, 11, 12)_b. The surface relief of the plates, examined by interference microscopy, was in the form of a simple tilt indicating an invariant plane strain transformation. The features of the transformation agreed with the predictions of the Bowles-MacKenzie theory of martensite formation. It was concluded that the morphology, structure and other characteristics of the freshly formed bainite plates were consistent with their formation by a thermally activated martensitic process. formerly Research Associate, Department of Metallurgy, University of British Columbia, Vancouver, B.C., Canada.     

Local orthogonal bases I: Construction

We present a new method for constructing local orthogonal bases, both in continuous and discrete time. All basis functions are obtained from a single prototype window, and there exists a fast algorithm for implementation. The approach is very general and can handle a large variety of cases interesting for applications, such as audio and image coding.     

Fostering scholarly productivity through academic and internship research training environments.

How can training programs foster counseling and clinical psychologists' scholarly productivity? This study examined the impact of academic and internship research training environments (RTEs) on the scholarly activity of 223 early career professionals. Results supported the construct validity of the Internship Research Training Environment scale through cross-validation and confirmatory factor analysis. Findings revealed differences in perceptions of the internship RTE and scholarly productivity as a function of academic training philosophy and internship training philosophy. Finally, results suggested that academic and internship RTEs could influence research interest and scholarly productivity indirectly by enhancing research self-efficacy and research outcome expectations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of complex grounding systems consisting of foundationgrounding systems with external grids

Results of an extensive research, conducted using a technique developed to calculate the grounding resistance of a complex grounding system consisting of a foundation grounding system with an external grid, buried in two-layer soil, are presented and discussed. It is shown that connecting a foundation grounding system to the already existing external grid provides only a small reduction of the overall grounding system resistance compared to the resistance of the external grid alone. A number of tables related to the most frequent cases of soil-concrete structures are given for practical assessment of the grounding resistance of such complex grounding systems     

A REGULARITY FOR CYCLIC CONJUGATION IN ACENAPHYHYLENE,FLUORANTHENE AND THEIR CONGENERS

Acenaphthylene, fluoranthene and their congeners are compounds that, in view of their chemical and physical properties, belong among benzenoid hydrocarbons. However, because of the presence of a five-membered ring, in all chemical-graph-theoretical considerations of benzenoid systems, these species have been disregarded. Continuing our recent studies of the title compounds, we report here on a peculiar characteristic of the pattern of their cyclic conjugation, named “the phenyl-cyclopentadienyl rule” (PCP rule): if a benzene ring is connected with the (unique) five-membered ring by exactly one carbon-carbon bond (which we refer to as a PCP constellation), then the cyclic conjugation in the five-membered ring significantly increases. If there are several PCP constellations, then the intensity of cyclic conjugation is additionally increased.     

Spray-dried nanoparticle-loaded pectin microspheres for dexamethasone nasal delivery

Abstract

In this study, we present the development of an innovative dry powder dexamethasone (Dex) nasal delivery system comprising Dex-loaded lipid/alginate nanoparticles incorporated within pectin microspheres (Dex/NPs-loaded pectin microspheres; DNM). DNM microspheres were characterized by the mean diameter of 2.76?±?0.10?µm, zeta-potential of –36.2?±?1.1?mV, and drug loading of 3.3?±?0.3%. The morphology study revealed irregular microsphere surface forming external voids. In contact with simulated nasal fluid, DNM microspheres demonstrated desirable property of moderate swelling and ensured stronger mucoadhesion compared with conventional Dex-loaded pectin microspheres. The strategy of Dex incorporation within the lipid/alginate NPs resulted in prolonged Dex release in relation to Dex being directly entrapped within the conventional pectin microspheres. DNM microspheres showed excellent biocompatibility and rendered Dex permeation across the selected epithelial cell model similar to that of Dex solution. In conclusion, balanced biopharmaceutical properties of the proposed nasal Dex delivery system provides the potential for prolonged contact time with nasal mucosa, prolonged therapeutic effect, and improved patient compliance.     

The impact of MAC parameters on the performance of 802.15.4 PAN

The operation of a personal area network, operating under the IEEE Standard 802.15.4 in the beacon enabled mode, is analyzed using the theory of discrete time Markov chains and M/G/1/K queues. The model includes the impact of different parameters such as packet arrival rate, number of stations, station’s buffer size, packet size, and inactive period between the beacons. We have derived several important performance parameters such as probability of access, probability that medium is idle, queue length distribution in the device, and probability distribution of the packet service time. Some important conclusions regarding the implementation of 802.15.4 networks and compatible network devices are outlined.     

Novel design approach for the creation of 3D geometrical model of personalized bone scaffold

Bone scaffolds provide a structural support for tissue development. Existing bone scaffolds are mainly characterized by complex porous designs whose shortcomings are a low level of permeability for growing tissue, and a difficult design customization. Scaffolds with nucleuses (rods or lattices) as basic elements should improve bone regeneration and enable higher design flexibility. In this paper, we present two new methods for building 3D geometrical models of personalized scaffolds, which are based on method of anatomical features. Methods are demonstrated in the case of scaffold for the mandible bone. This approach greatly reduces the designer effort and time, while enabling easy personalization of scaffolds’ shape and geometry.