A tightly coupled numerical foil bearing solution

Equations describing the steady-state flying height of magnetic tape over a recording head are solved using an algorithm that incorporates a linearized approximation of air bearing stiffness into the tape equation. The one-dimensional infinitely wide equations include compressibility and slip flow in the air bearing, as well as tension, momentum, and flexural rigidity in the tape. The stiffness coupling between the equations allows simulation of complicated head geometries and reduces the computational effort required to determine the steady-state flying height by more than an order of magnitude compared to previously published methods which are based on time-dependent equations. Two example problems are presented, both of which were solved on a personal computer in under one minute     

Langmiur–Blodgett studies of silicon(IV) phthalocyanine bis(trihexylsilyoxide) and its optical properties

Although much solution-based research has been carried out on silicon phthalacyanines, little work has been done on Si Pc LB films. In order to attempt studies on thin films, ultrathin Langmuir–Blodgett films of silicon(IV) phthalocyanine bis(trihexylsilyoxide), C₆₈H₉₄N₈O₂Si₃ have been studied and characterised. Whilst silicon(IV) phthalocyanine bis(trihexylsilyoxide) is not a traditional LB film forming material, it can be made conducive to deposition by mixing with ideal film forming materials such as calixarenes. Surface pressure–area isotherms revealed an area per molecule of around 7.5 Å² which indicates that the silicon(IV) phthalocyanine bis(trihexylsilyoxide) forms multi-lamella stacks. Thermal optical polarised spectroscopy revealed the formation of brightly coloured mesophases in films. DSC showed the presence of an irreversible A phase and a reversible T phase.     

Measurement of IP3 in p-i-n photodetectors and proposed performancerequirements for RF fiber-optic links

The nonlinearities generated by wide-band, high-current photodetectors are discussed in the context of the performance of an externally modulated analog radio-frequency fiber-optic link. The quantitative impart of the detector's third-order intermodulation product intercept (IP3) on the link's spur-free dynamic range is analyzed. Waveguide p-i-n photodiodes were developed to specifically address these stringent IP3 goals. The IP3 was measured using a four laser heterodyne system resulting in an IP3 of 27 dBm measured at a center frequency of 20 GHz with 20 mA of de photocurrent. The authors believe that this is the highest photodetector IP3 reported to date at these operating conditions     

Process optimization for high electron mobility in nMOSFETs with aggressively scaled HfO/sub 2//metal stacks

The performance of aggressively scaled (1.4nm相似文献   

Evidence of multiple mechanisms of avermectin resistance in haemonchus contortus--comparison of selection protocols

The ginsenosides Rb1 and Rg1, the major components of ginseng saponin, inhibited not only methamphetamine-induced hyperactivity but also conditioned place preference (CPP) in mice following a single or repeated administration. Dopamine (DA) receptor supersensitivity, which developed in methamphetamine-induced CPP mice, was also inhibited by both Rb1 and Rg1. Therefore, the present results suggest that Rb1 and Rg1 may be the active components of ginseng saponin in the modulation of methamphetamine-induced dopaminergic behaviors such as hyperactivity and CPP, supporting our previous conclusion that ginseng saponin might modulate methamphetamine-induced dysfunction at both the pre- and postsynaptic DA receptors.     

Endobronchial tumours in childhood

Like psychomotor stimulants, a weak amphetamine-like agent, such as phenylpropanolamine, enhances the analgesic effects of morphine (MOR). Thus, it is possible that full psychomotor stimulant potency is not required to increase the analgesic action of opiates. The validity of this assumption is here tested by studying the ability of (-)-norpseudoephedrine (NPE), an enantiomer of phenylpropanolamine and a metabolite of cathinone, to influence both the analgesic effects of MOR and its discriminative stimulus properties. In mice NPE (5.6-10.0-17.0 mg/kg i.p.) did not prolong the latency to lick or to remove paws from a plate warmed at 54 degrees C. However, it significantly potentiated the analgesic effect of 3.2 mg/kg of MOR. These results were replicated in rats by use of the formalin test, which measures the numbers of hind paw flinches produced by injecting 50 microl of formalin into the dorsal surface of the paw. The higher dose of NPE (17 mg/kg) increased the effect of sub-analgesic doses of MOR (0.56 and 1.0 mg/kg). In rats trained to discriminate between 0.5 mg/kg of amphetamine and solvent in a two-lever operant behavior reinforced by water access. NPE induced a dose-dependent increment of drug lever responding from 0% at 1.0 mg/kg to 100% at 32.0 mg/kg. In contrast, NPE did not generalize for the MOR cue up to the dose of 56.0 mg/kg, which produced a substantial reduction of the response rate. However, when given in combination, NPE attenuated the discriminative effects of MOR and potentiated its inhibitory action on the response rate. These results exclude a direct action of NPE on the mu opiate system. In conclusion, NPE preserves amphetamine-like properties and these properties are probably responsible for the interaction of the drug with the analgesic and discriminative effects of MOR. Therefore, this study contradicts the assumption that the analgesic effects of MOR can be enhanced by a sympathomimetic drug that lacks significant psychostimulant actions.     

Variation in relative quantities of airborne sex pheromone components from individual femaleEphestia cautella (Lepidoptera: Pyralidae)

The airborne sex pheromone components (Z,E)-9,12-tetradeca-dien-1-yl acetate and (Z)-9-tetradecen-1-y1 acetate from single calling females ofEphestia cautella (Walker) were trapped within glass capillary tubes and were measured by gas chromatography-mass spectrometry. Broad and similar distributions of relative quantities were found for a laboratory strain and three Australian field strains, and means differed strongly from those reported previously for this species. The overall mean proportion of the two components found for Australian females was 8812. The composition in individuals ranged from 6327 to 973. The proportions for individuals appeared to vary slightly in a random fashion from day to day, and proportions for first-generation progeny were influenced by the maternal blend.Author order in this paper is alphabetical     

Dynamic and static characteristics of a wide speed range machine tool spindle

The static and dynamic stiffnesses of spindle-bearing systems are examined. It is shown that for most general purpose spindle designs spring or hydraulically preloaded bearing arrangements can produce more rigid spindles than comentational bearing arrangements. It is also argued that adjustable preload enables bearing damping to be matched to the spindle-bearing system to give maximum dynamic stiffness. The RHP Variload bearing arrangement is introduced.