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51.
52.
Courts routinely award coverage for TMJ disorders under medical plans, despite exclusionary language and evidence that the insured failed to disclose preexisting treatment as required by the plan and neglected to attempt more conservative treatment first. Such decisions adversely affect both the health carrier and the plan participants. Various states have enacted legislation mandating coverage of TMJ; however, TMJ issues still exist and will remain a frequent topic for litigation until the judiciary recognizes that validating contract language ultimately benefits insureds as consumers and reinforces the integrity of the industry as a whole. 相似文献
53.
An improved physical understanding of the rotor aerodynamics of a horizontal axis wind turbine (HAWT) is required to reduce the uncertainties associated with today's design codes. Wind tunnel experiments contribute to increased knowledge and enable validation and construction of models. The present study focuses on the near‐wake of a model HAWT in both axial and yawed flow conditions. At three downstream planes parallel to the rotor plane, single‐sensor hot‐film traverses are made. The phase‐locked unsteady three‐dimensional flow velocity vector is determined by a novel data reduction method. A series of two papers discusses the near‐wake aerodynamics of a model HAWT. The main goals are to obtain a detailed understanding of the near‐wake development and to arrive at a base for model construction and validation. The first paper presents the experimental setup, data reduction and the results for the baseline case (axial flow conditions). In the second paper, the results for the yawed flow cases are presented and the effect of yaw misalignment on the near‐wake development is discussed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
54.
Due to their large specific surface and their abundance, micro and nano particles play an important role in the transport of micropollutants in the environment. Natural particles are usually composed of a mixture of inorganic amorphous or crystalline material (mainly FeOOH, Fe(x)Oy, Mn(x)Oy and clays) and organic material (humics and polysaccharides). They all tend to occur as very small particles (1-1,000 nm in diameter). Most natural amorphous particles are unstable and tend to transform with time towards more crystalline forms, either by aging or possibly, by dissolution and re-crystallization. Such transformations affect the fate of sorbed micropollutants and the scavenging properties are therefore changed. As these entities are sensitive to dehydration (aggregation, changes in the morphology), it is highly important to observe their morphology in their natural environment and understand their composition at the scale of the individual particles. Also for the understanding and optimization of water treatment technologies, the knowledge of the occurrence and behavior of nano-particles is of high importance. Some of the possible particle analysis methods are presented: aggregation processes, biomineralization, bacterial adhesion, biofilms in freshwaters, ferrihydrite as heavy metals remover from storm water. These examples demonstrate the capabilities and focus of the microscopes. Atomic Force Microscopy (AFM) allows to analyze the particles in their own environment, meaning in air or in the water. Thus, native aspects of particles can be observed. As well, forces of interactions between particles or between particles and other surfaces such as membranes will be highly valuable data. Scanning Electron Microscopy (SEM) and for higher lateral resolution, Transmission Electron Microscopy (TEM) allow measurement of the morphology and composition. Especially, TEM coupled with Electron Energy Loss Spectroscopy (TEM-EELS) is a powerful technique for elemental analysis. Finally, general guidelines for the effective use of microscopic techniques are provided. 相似文献
55.
Jeff T. M. De Hosson Wouter A. Soer Andrew M. Minor Zhiwei Shan Eric A. Stach S. A. Syed Asif Oden L. Warren 《Journal of Materials Science》2006,41(23):7704-7719
As a tribute to the scientific work of Professor David Brandon, this paper delineates the possibilities of utilizing in situ transmission electron microscopy to unravel dislocation-grain boundary interactions. In particular, we have focused on the deformation characteristics of Al–Mg films. To this end, in situ nanoindentation experiments have been conducted in TEM on ultrafine-grained Al and Al–Mg films with varying Mg contents. The observed propagation of dislocations is markedly different between Al and Al–Mg films, i.e. the presence of solute Mg results in solute drag, evidenced by a jerky-type dislocation motion with a mean jump distance that compares well to earlier theoretical and experimental results. It is proposed that this solute drag accounts for the difference between the load-controlled indentation responses of Al and Al–Mg alloys. In contrast to Al–Mg alloys, several yield excursions are observed during initial indentation of pure Al, which are commonly attributed to the collective motion of dislocations nucleated under the indenter. Displacement-controlled indentation does not result in a qualitative difference between Al and Al–Mg, which can be explained by the specific feedback characteristics providing a more sensitive detection of plastic instabilities and allowing the natural process of load relaxation to occur. The in situ indentation measurements confirm grain boundary motion as an important deformation mechanism in ultrafine-grained Al when it is subjected to a highly inhomogeneous stress field as produced by a Berkovich indenter. It is found that solute Mg effectively pins high-angle grain boundaries during such deformation. The mobility of low-angle boundaries is not affected by the presence of Mg.Special title: Advanced Materials and Characterization: Proceedings of the Brandon Symposium; Guest Editors: Wayne D. Kaplan and Srinivasa Ranganathan 相似文献
56.
Sabine Bertho Ilse Haeldermans Ann Swinnen Wouter Moons Tom Martens Laurence Lutsen Dirk Vanderzande Jean Manca Alessia Senes Annalisa Bonfiglio 《Solar Energy Materials & Solar Cells》2007,91(5):385-389
A new approach is presented in order to improve the thermal stability of polymer: [6-6]-phenyl C61 butyric acid methyl ester (PCBM) bulk heterojunction solar cells. The central idea in this approach is the use of a polymer with high glass transition temperature (Tg), well above the normal operating temperatures of the devices. In this paper, a PPV-derivative with a Tg of 150 °C was used as an electron donor and the thermal stability of the obtained solar cells was compared with solar cells based on the reference material poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene] (MDMO-PPV) with a Tg of 45 °C. The use of the material with higher glass transition temperature resulted in a significant improvement of the thermal stability of the photovoltaic parameters. Furthermore, a systematic transmission electron microscope (TEM) study demonstrates that the better thermal stability of performance coincides with a more stable active layer morphology. Both improvements are attributed to the reduced free movement of the electron donor material (PCBM) within the active layer of the solar cell. 相似文献
57.
Riccioli C Pérez-Marín D Guerrero-Ginel JE Saeys W Garrido-Varo A 《Applied spectroscopy》2011,65(7):771-781
This paper proposes a method based on near-infrared hyperspectral imaging for discriminating between terrestrial and fish species in animal protein by-products used in livestock feed. Four algorithms (Mahalanobis distance, Kennard-Stone, spatial interpolation, and binning) were compared in order to select an appropriate subset of pixels for further partial least squares discriminant analysis (PLS-DA). The method was applied to a set of 50 terrestrial and 40 fish meals analyzed in the 1000-1700 nm range. Models were then tested using an external validation set comprising 45 samples (25 fish and 20 terrestrial). The PLS-DA models obtained using the four subset-selection algorithms yielded a classification accuracy of 99.80%, 99.79%, 99.85%, and 99.61%, respectively. The results represent a first step for the analysis of mixtures of species and suggest that NIR-CI, providing valuable information on the origin of animal components in processed animal proteins, is a promising method that could be used as part of the EU feed control program aimed at eradicating and preventing bovine spongiform encephalopathy (BSE) and related diseases. 相似文献
58.
Size-exclusion chromatography in combination with organic carbon detection (SEC-OCD) is an established method to separate the pool of NOM into major fractions of different sizes and chemical functions and to quantify these on the basis of organic carbon. One specific approach, also known as LC-OCD-OND, is based on the Gräntzel thin-film UV-reactor. This approach is described with recent improvements in fraction assignation (humic substances, biopolymers, building blocks, low molecular weight organic acids and neutrals, hydrophobic organic carbon), the coupling of a novel organic nitrogen detector (OND), and an improved diagram for the characterisation of aquatic humic substances (HS-diagram). The diagram replaces the operational distinction between humic and fulvic acids by a continuum ranging from aquagenic fulvic acids to pedogenic humic acids. 相似文献
59.
Wouter A. Serdijn Albert C. Van Der Woerd Jan Davidse Arthur H. M. Van Roermund 《Analog Integrated Circuits and Signal Processing》1995,8(2):131-143
This paper discusses the design of low-voltage low-power fully-integratable automatic gain controls. Four different AGCs are presented, all consisting of three elementary building blocks: a controlled amplifier, a comparator and a voltage follower. Their design is treated separately. As an example, the final section describes an automatic gain control for hearing instruments, realized in a bipolar process. 相似文献
60.
Influence of solute type and concentration on ice scaling in fluidized bed ice crystallizers 总被引:1,自引:0,他引:1
During crystallization of ice from aqueous solutions, ice crystals exhibit a marked tendency to adhere to the cooled heat exchanger wall resulting in the formation of an insulating ice layer, often referred to as ice scaling. A promising method to avoid ice scaling is the application of a solid-liquid fluidized bed heat exchanger in which fluidized steel particles remove the ice crystals from the walls. This paper presents experiments with a single-tube fluidized bed heat exchanger in which ice crystals were produced from aqueous solutions of various solutes with varying concentrations. The experiments reveal that ice scaling is only prevented when a certain temperature difference between wall and solution is not exceeded. This transition temperature difference appears to increase approximately linearly with the solute concentration and is higher in aqueous solutions with low diffusion coefficients. The observed phenomena are explained by the hypothesis that ice scaling is only prevented when the mass transfer controlled growth rate of ice crystals on the wall does not exceed the scale removal rate induced by the fluidized steel particles. In conclusion, a model based on these physical phenomena is proposed to predict ice scaling in fluidized bed heat exchangers. 相似文献