Application of ion-induced nucleation mass spectrometry in the analysis of trace gases evolved from a polyimide film during the thermal curing stages

Trace gases evolved from a polyimide film during its thermal curing stages have been studied using ion-induced nucleation mass spectrometry. The technique involved exposing the test gas sample to a low energy beta source and recording the masses of the ion-induced molecular clusters formed in the reaction chamber. On the basis of the experimentally observed molecular cluster spectra, it has been concluded that the dominant trace component had a molecular weight of 87 atomic mass units. This component has been identified as a molecule of dimethylacetamide (DMAC) which had been used as a solvent in the preparation of the test polyimide specimen. This identification has been further confirmed by comparing the spectra of the test gas sample and the DMAC calibration sample obtained with a conventional mass spectrometer. The advantages of the ion-induced nucleation mass spectrometer versus the conventional mass spectrometer are discussed

Characterisation of sol-gel PZT films on Pt-coated substrates

A conventional sol-gel process was used to spin-cast PZT films on oxidized Si wafers coated with sputtered Pt layers. After annealing at 550 degrees C-800 degrees C, the resulting perovskite-type PZT films showed different textures and surface morphologies, depending on whether or not a Ti adhesion layer was used. If a Ti layer was present, Ti diffusion into and through the Pt film leads to a compound Pt3Ti, which facilitates crystallization of the perovskite PZT phase; without Ti, crystallization is more difficult and occurs via the growth of dendritic crystallites. Several optical and electrical properties of the PZT films have been measured; the first results indicate high dielectric constants ( epsilon approximately=480) and acceptable ferroelectric behaviour

GAROL - A computer program for evaluating resonance absorption including resonance overlap

GAROL computer program for neutron resonance absorptio

Spectral Response of the Pulsationally-Induced Shocks in the Atmosphere of BW Vulpeculae

The star BW Vul excites an extremely strong radial pulsation that grows in its envelope and is responsible for visible shock features in the continuum flux and spectral line profiles emerging in the atmosphere At two phases separated by 0.8 cycles. Material propelled upwards in the atmosphere from the shock returns to the lower photosphere where it creates a second shock just before the start of the next cycle. We have obtained three nights of echelle data for this star over about 5 pulsation cycles (P = 0.201 days) in order to evaluate the effects of on a number of important lines in the spectrum, including the HeI 5875A and 6678A lines. These data were supplemented by archival high-dispersion IUE (UV) data from 1994. A comparison of profiles of the two HeI lines during the peak of the infall activity suggests that differences in the development of the blue wing at this time are due to heating and short-lived formations of an optically thin layer above the atmospheric region compressed by the infall. This discovery and the well-known decreases in equivalent widths of the CII 6578-83A doublet at the two shock phases, suggests that shock flattens the temperature gradient and produces heating in heating the upper atmosphere. Except for absorptions in the blue wings of the UV resonance lines, we find no evidence for sequential shock delays arriving at various regions of line formation of the photosphere (a "Van Hoof effect"). Phase lags cited by some former observers may be false indicators arising from varying degrees of desaturation of multiple lines, such as for the red HeI lines. In addition, an apparent lag in the equivalent width curve of lines arising from less excited atomic levels could instead be caused by post-shock cooling, followed by a rebound shock.Comment: 12 pages in Latex/MNRAS format, 9 eps-format figure

A new HCN maser in IRAS 15082-4808

We have identified a new vibrational HCN maser at 89.087 GHz in the asymptotic giant branch (AGB) star IRAS 15082-4808, a maser which is thought to trace the innermost region of an AGB envelope. The observations of this maser at three epochs are presented: two positive detections and one null detection. The line profile has varied between the positive detections, as has the intensity of the maser. The major component of the maser is found to be offset by -2.0+/-0.9 km/s with respect to the systemic velocity of the envelope, as derived from the 88.631 GHz transition of HCN. Similar blueshifts are measured in the other 9 sources where this maser has been detected. Maser variability with pulsation phase has been investigated for the first time using the 10 stars now available. Comparisons with AGB model atmospheres constrain the position of the formation region of the maser to the region between the pulsation shocks and the onset of dust acceleration, between 2 and 4 stellar radii.Comment: 11 pages, 10 figures, accepted MNRAS, minor correction to equation

Mechanized fluid connector and assembly tool system with ball detents

A fluid connector system is disclosed which includes a modified plumbing union having a rotatable member for drawing said union into a fluid tight condition. A drive tool is electric motor actuated and includes a reduction gear train providing an output gear engaging an integral peripheral spur gear on the rotatable member. Coaxial alignment means are attached to both the connector assembly and the drive tool. A hand lever actuated latching system includes a plurality of circumferentially spaced latching balls selectively wedged against the alignment means attached to the connector assembly or to secure the drive tool with its output gear in mesh with the integral peripheral spur gear. The drive motor is torque, speed, and direction controllable

Automobile ride quality experiments correlated to iso-weighted criteria

As part of an overall study to evaluate the usefulness of ride quality criteria for the design of improved ground transportation systems an experiment was conducted involving subjective and objective measurement of ride vibrations found in an automobile riding over roadways of various roughness. Correlation of the results led to some very significant relationships between passenger rating and ride accelerations. The latter were collapsed using a frequency-weighted root mean square measure of the random vibration. The results suggest the form of a design criterion giving the relationship between ride vibration and acceptable automobile ride quality. Further the ride criterion is expressed in terms that relate to rides with which most people are familiar. The design of the experiment, the ride vibration data acquisition, the concept of frequency weighting and the correlations found between subjective and objective measurements are presented

Venture capital and risk in high-technology enterprises

We find UK investors and entrepreneurs are significantly concordant in rankings of investments and key factors for risk but significantly discordant on risk classes. Investors emphasise agency risk (e.g., motivation, empowerment, alignment), and entrepreneurs emphasise business risk (e.g., market opportunities)

Evidence of a saturated gravity-wave spectrum throughout the atmosphere

The view adapted here is that the dominant mesoscale motions are due to internal gravity waves and show that previous and new vertical wave number spectra of horizontal winds are consistent with the notion of a saturation limit on wave amplitudes. It is also proposed that, at any height, only those vertical wave numbers m less than m sub asterisk are at saturation amplitudes, where m sub asterisk is the vertical wave number of the dominant energy-containing scale. Wave numbers m less than m sub asterisk are unsaturated, but experience growth with height due to the decrease of atmospheric density. The result is a saturated spectrum of gravity waves with both m sub asterisk decreasing and wave energy increasing with height. This saturation theory is consistent with a variety of atmospheric spectral observations and provides a basis for the notion of a universal spectrum of atmospheric gravity waves

Venture capital investor behaviour in the backing of UK high technology firms : financial reporting and the level of investment

This paper is an empirical investigation into the ways in which venture capitalists value (and invest in) high technology firms, focusing on financial reporting, risk disclosure and intangible assets. It is based on questionnaire returns from UK investors in diverse sectors, ranging from biotechnology, through software/ computer services, to communications and medical services. This evidence is used to examine: (a) the usefulness of financial accounts; (b) the implications of technopole investment; (c) the extent of investor control over the investee's AIS; and (d) the role of investor opinion (e.g. on disclosure, due diligence and risk reporting) in determining the level of equity provision