Interlaminar shear properties of some glass-fiber-reinforced phenolic and polyester laminates

Chopped strand mat and glass-fabric-reinforced thin and thick laminates were made from phenolic and polyester laminating resins using three modifications of a hand lay-up method. Short-beam interlaminar shear strengths were determined in three-point bending at a span-to-depth ratio 3:1. Plane and perpendicular specimens were used. It was found that the perpendicular specimens were more useful. Interlaminar delamination energies were determined statically and dynamically. It was found that the results for the phenolic and polyester laminates cannot be simply compared because of differences in the fracture mechanism.     

Maintenance of H? antagonists self-injection in baboons.

The ability of H? histamine receptor antagonists to maintain self-injection in baboons using a cocaine substitution procedure was evaluated. Vehicle or a drug dose was substituted for cocaine (0.32 mg/kg/injection) for a period of 15 or more days. Tripelennamine (0.32 mg/kg/injection) and diphenhydramine (1.0 mg/kg/injection) maintained moderate-to-high rates of self-injection. Chlorpheniramine maintained low-to-moderate rates of self-injection. Promethazine did not reliably maintain self-injection, but rather, suppressed responding relative to control in 2 of 3 baboons (Papio cynocephalus). High doses of tripelennamine, diphenhydramine, and chlorpheniramine initially suppressed food intake and produced signs of behavioral toxicity, including agitation and sometimes seizures. These data demonstrate that H? antagonists can serve as reinforcers and produce behavioral toxicity in the baboon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computer program for calculation of kinetic and pharmacologic parameters using a 'direct linear plot' derived algorithm

Data processing using nonparametric statistics was performed using a 'direct linear plot' algorithm of ECB. ECB (Eisenthal and Cornish-Bowden) is a computer program designed to calculate the Km and V parameters in enzyme kinetics. It is also suitable for estimation of EC50 (ligand or drug concentration for 50% effect) in pharmacological studies.     

Dispersion Measurement in Optical Fibers Using Supercontinuum Pulses

The chromatic dispersion of an optical fiber is measured using a time-of-flight technique, based on temporally and spectrally resolving a dispersed broadband pulse, on which a spectral fringe pattern has been imposed using an etalon. The technique employs broadband supercontinuum radiation, generated by launching picosecond pulses from a fiber laser into a photonic- crystal fiber. It allows the dispersion of highly dispersive optical fibers and components to be measured with a high spectral resolution over a wide wavelength region. The technique is demonstrated by measuring the dispersion of a dispersion-compensating module over its entire 400-nm transmission band with a subnanometer spectral resolution.     

Eye muscle sparing by the muscular dystrophies: lessons to be learned?

The devastating consequences of the various muscular dystrophies are even more obvious when a muscle or muscle group is spared. The study of the exceptional cell or tissue responses may prove to be of considerable value in the analysis of disease mechanisms. The small muscles responsible for eye movements, the extraocular muscles, have functional and morphological characteristics that set them aside from other skeletal muscles. Notably, these muscles are clinically unaffected in Duchenne/Becker, limb-girdle, and congenital muscular dystrophies, pathologies due to a broken mechanical or signaling linkage between the cytoskeleton and the extracellular matrix. Uncovering the strategies used by the extraocular muscles to "naturally" protect themselves in these diseases should contribute to knowledge of both pathogenesis and treatment. We propose that careful investigation of the cellular determinants of extraocular muscle-specific properties may provide insights into how these muscles avoid or adapt to the cascade of events leading to myofiber degeneration in the muscular dystrophies.     

Optical detection of the anesthetic agent propofol in the gas phase

The anesthetic agent propofol (2,6-diisopropylphenol) is the most widely used intravenously administered drug in general anesthesia. However, a viable online capability to monitor metabolized levels of propofol in patients does not currently exist. Here we show for the first time that optical spectroscopy has good potential to detect metabolized propofol from patients' exhaled breath. We present quantitative absorption measurements of gas phase propofol both in the ultraviolet and middle-infrared spectral regions. We demonstrate that a detection limit in the subparts-per-billion concentration range can be reached with photoacoustic spectroscopy in the UV spectral region, paving the way for the development of future optical monitors.     

Influence of the Al(Co,Ni) layer on the corrosion resistance of a cobalt based alloy (Mar‐M‐509®)

In the present work, the results of studies on the structure and corrosion resistance of Al(Co, Ni) layer are shown. The diffusion Al(Co, Ni) layer was created on the cobalt alloy Mar‐M‐509 substrate by chemical vapor deposition (CVD) method with aluminum trichloride (AlCl₃) under the hydrogen atmosphere. The scanning electron microscope (SEM) observations and microtomography measurements of layers were performed. Also an analysis of the chemical (energy‐dispersive X‐ray spectroscopy (EDS)) and phase (X‐ray diffraction (XRD)) composition was carried out. By the X‐ray diffraction method (sin² φ) also the residual stresses were calculated in the matrix of the material. The corrosion resistance was tested with impedance and potentiodynamic methods in 0.1 M Na₂SO₄, 0.1 M H₂SO₄ solutions and acidulous 0.1 M NaCl solution (pH = 4.2) at room temperature. The results indicate that the analyzed layer with a thickness of about 14 μm have a similar corrosion resistance compared to the base material – Mar‐M‐509^® cobalt alloy. Only in the strongly acidic environments, the corrosion resistance of the layer is remarkably decreased.     

Corrosion of aluminum electrodes in aqueous slurries for lithium-ion batteries

Current manufacturing methods for lithium ion batteries use a non-aqueous solvent for producing slurries of cathode active materials and applying them to the aluminum current collectors. Transition to a water-based process may be desirable to reduce volatile organic compound emissions and costs, and increase processing efficiency. This transition may lead to additional complexities such as corrosion that could impact the performance of cells in service. The current work shows that the use of aqueous-based slurries for manufacturing lithium ion batteries can lead to general and pitting corrosion of the aluminum alloy foils used as current collectors with contact times as short as 100 s. Pitting corrosion initiates due to localized galvanic cells between cathodic intermetallic particles present in the aluminum alloy and the locally anodic aluminum matrix. The extent of pitting and amount of general corrosion product formed differs when using slurries of different active material compositions and increases with slurries of higher inherent pH. The presence of the intermetallic particles in the aluminum alloy is expected based on the chemical composition of the material. While elimination of the intermetallics from the aluminum is possible by increasing the purity of the material, it is unlikely that this mitigation strategy would be implemented due to economic considerations.     

Conjugate natural convection in a square enclosure: effect of conduction in one of the vertical walls

Steady, laminar, natural convection flow in a square enclosure has been analysed numerically. One vertical wall of the enclosure is thick, with a finite thermal conductivity, while the other three walls are taken to be of zero thickness. The problem is conjugate and the main focus of the study is on examining the effect of conduction in the wall on the natural convection flow in the enclosure. Three separate models to account for the wall conduction are investigated : (i) the complete conjugate case in which conduction in the thick vertical wall is assumed to be fully two-dimensional; (ii) a one-dimensional model in which conduction in the wall is assumed to be in the horizontal direction only; and (iii) a lumped parameter approach which assumes the solid-fluid interface temperature to be uniform. A Boussinesq fluid with Prandtl number of 0.7 (air) and Grashof numbers ranging from 10³ to 10⁷ are considered. For Grashof number > 10⁵, the temperature distribution in the wall shows significant two-dimensional effects and the solid-fluid interface temperature is found to be quite non-uniform. This non-uniformity tends to make the flow pattern in the enclosure asymmetric. In the parametric range investigated, all three models predict nearly the same value for the overall heat transfer.     

汽油和柴油混合燃料均质压燃(HCCI)的试验研究

汽油和柴油这两种不同特性的燃料被用作HCCI发动机的燃料。汽油具有高挥发性、易雾化和易于形成混合气的特性,被用来形成均质混合气;柴油具有良好的着火性和可燃性,被用来控制自燃和限制爆震燃烧。期望这两种特性不同而又相互补充的燃料混合后能够达到一个折衷的HCCI的燃烧性能。试验在一个专用于HCCI研究的单缸发动机上实施,采用两种中等的压缩比(10．4和15)和两种HCCI模式(进气加热和负气门叠开),试验结果证实了这种期望。结果是:随着混合燃料中柴油比例的增加,对于进气加热模式,HC- CI能稳定工作所需要的进气温度有所降低,对于负气门叠开模式,缸内平均指示压力和过量空气系数的范围有所扩展,并且两种方式下HC和NOx的排放均有所减少。