Theorizing gender in the face of social change: Is there anything essential about essentialism?

The authors examine how beliefs about the stability of the social hierarchy moderate the link between sexism and essentialist beliefs about gender and how the expression of essentialist beliefs might reciprocally affect the social structure. Studies 1 (N = 240) and 2 (N = 143) presented gender-based inequality as stable, changing, or changed. In both studies, sexism was positively associated with essentialism only among men and only when inequality was presented as changing. Study 3 (N = 552) explored the possible consequences of expressing essentialist theories for social change. Exposure to essentialist theories increased both men's and women's acceptance of inequality. Exposure further increased men's support for discriminatory practices and boosted their self-esteem. These patterns demonstrate that although essentialism is linked to prejudice, this link is itself not essential. Rather, essentialism may be invoked strategically to protect higher status when this is threatened by change and may be successful in so doing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency response subtraction for simple measurement of intrinsiclaser dynamic properties

The authors describe a new technique for extracting the intrinsic laser-diode dynamic properties accurately. This simple technique eliminates the need for accurate microwave calibration of the test equipment and problems of microwave reflections, nonideal frequency response of laser mount, and detector. The effect of the parasitic components of the laser diode are also eliminated from the results so that measurements of important dynamic properties of the laser can be found up to high frequencies (10-20 GHz) on standard laser diodes. The techinque being used to measure variations of resonance peak and damping factor at different bias levels for a standard bulk active region 1.3 μm laser diode is shown     

The work of fracture of random fibre reinforced cement

From considerations of the pull-out behaviour of individual inclined wires from model composites, the work of fracture and post-cracking stress of random fibre reinforced composites have been estimated. Results are presented for cement composites reinforced with short, high-strength steel wires. It was found that when the fibres were short and/or the interfacial shear stress low, a substantial part of the composite work of fracture was due to plastic deformation of those fibres which were not perpendicular to the matrix crack face. Under such conditions random fibre composites showed superior properties than aligned composites of the same volume fraction of reinforcement.

---

Résumé On a évalué le travail de rupture et la contrainte après fissuration de matériaux renforcés de fibres à répartition aléatoire à partir de l'étude de modèles de composites dans lesquels on a considéré le comportement à l'arrachement de filaments individuels inclinés. Les résultats donnés ici se rapportent à des composites à base de ciment renforcé avec de courts filaments d'acier de haute résistance. On constate que lorsque les fibres sont courtes et/ou la contrainte de cisaillement à l'interface faible, une part substantielle du travail de rupture est due à la déformation plastique des fibres qui ne sont pas perpendiculaires à la surface fissurée. Dans de telles conditions, les composites à fibres réparties au hasard montrent des proprietés meilleures que les composites à fibres alignées pour le même rapport de volume de renforcement.

     

Television Sound Subcarrier Transmission in Space Communication

In a nonideal transmission enviromnent, the transmission of video sound in the form of an FM subcarrier above the video baseband causes interactions between video and sound subcarrier which result in signal distortion. The degree of distortion depends on the type of channel impairments and the selection of transmission parameters. While the fidelity of the video signal can be preserved by mainly limiting the subcarrier level, the quality of the audio channel can be optimized by choosing the right subcarrier frequency. It can be shown that for a given video-carrier-to-noise ratio, subcarrier power below video signal power, and for given system impairments, there exists an optimum subcarrier location which provides a maxinum audio-signal-to-noise ratio.     

Kinetics of emitted mass—A study with three dry powder inhaler devices

The purpose of this study was to understand the kinetics of emptying of micronised salbutamol sulphate (SS) and lactohale 300 (LH300) under varying air flow rates (30–180 L min⁻¹) from three dry powder inhaler devices, Rotahaler^® (RH), Monodose Inhaler^® (MI) and Handihaler^® (HH). Aerosol concentration vs. time profiles, determined through real-time laser diffraction particle sizing, demonstrated that the majority of the powder from RH was emitted within one second while a more prolonged aerosolisation was observed from MI and HH. Peak aerosol concentrations were achieved more rapidly from RH compared to MI for both SS and LH300. Calculated cumulative emitted mass (CCEM) vs. time profiles were obtained from the aerosol concentration vs. time profiles and the emitted mass and the rate of CCEM (k_CCEM), estimated from a modelling approach, increased with increasing air flow rates. The k_CCEMvs. air flow rate profiles of SS and LH300 were significantly different at high air flow rates. The k_CCEM was highest from RH and lowest from MI. Differences in k_CCEM between the devices were related to capsule aperture size while the differences between the materials were due to the powder bed structure. This approach provided an understanding of the rate at which powder mass emptied from dry powder inhaler devices and was proposed to be a powerful development tool for the future powder inhalers.     

Radiometric correction of multi-temporal Landsat data for characterization of early successional forest patterns in western Oregon

Detecting and characterizing continuous changes in early forest succession using multi-temporal satellite imagery requires atmospheric correction procedures that are both operationally reliable, and that result in comparable units (e.g., surface reflectance). This paper presents a comparison of five atmospheric correction methods (2 relative, 3 absolute) used to correct a nearly continuous 20-year Landsat TM/ETM+ image data set (19-images) covering western Oregon (path/row 46/29). In theory, full absolute correction of individual images in a time-series should effectively minimize atmospheric effects resulting in a series of images that appears more similar in spectral response than the same set of uncorrected images. Contradicting this theory, evidence is presented that demonstrates how absolute correction methods such as Second Simulation of the Satellite Signal in the Solar Spectrum (6 s), Modified Dense Dark Vegetation (MDDV), and Dark Object Subtraction (DOS) actually make images in a time-series somewhat less spectrally similar to one another. Since the development of meaningful spectral reflectance trajectories is more dependant on consistent measurement of surface reflectance rather than on accurate estimation of true surface reflectance, correction using image pairs is also tested. The relative methods tested are variants of an approach referred to as “absolute-normalization”, which matches images in a time-series to an atmospherically corrected reference image using pseudo-invariant features and reduced major axis (RMA) regression. An advantage of “absolute-normalization” is that all images in the time-series are converted to units of surface reflectance while simultaneously being corrected for atmospheric effects. Of the two relative correction methods used for “absolute-normalization”, the first employed an automated ordination algorithm called multivariate alteration detection (MAD) to statistically locate pseudo-invariant pixels between each subject and reference image, while the second used analyst selected pseudo-invariant features (PIF) common to the entire image set. Overall, relative correction employed in the “absolute-normalization” context produced the most consistent temporal reflectance response, with the automated MAD algorithm performing equally as well as the handpicked PIFs. Although both relative methods performed nearly equally in terms of observed errors, several reasons emerged for preferring the MAD algorithm. The paper concludes by demonstrating how “absolute-normalization” improves (i.e., reduces scatter in) spectral reflectance trajectory models used for characterizing patterns of early forest succession.     

THE PETROLOGY OF THE MIDDLE JURASSIC SANDSTONES FROM THE MURCHISON FIELD, NORTH SEA

A petrographical investigation of the sandstones of the Brent Group (Middle Jurassic) from the Murchison field has produced evidence for the existence of two transgressive events within the sequence, one occurring immediately above the Etive Fm., the other within the upper part of the Ness Fm. These transgressions have not been previously recorded in Murchison and their discovery demands that some modification be made to the existing depositional model for the Brent Group of this area. A volcanic ash horizon has been found in a similar stratigraphic position to that recorded from Statfjord, and if this, and the two transgressive horizons noted above, are of more than local extent they could prove to be useful stratigraphic markers.
Although the diagenesis of the Brent Group sandstones in Murchison differs little from that recorded elsewhere in the Brent province, the interpretation of the timing of the development of certain phases differs somewhat from those of other authors. In particular, kaolinite development appears to have taken place soon after burial in response to periods of emergence and weathering during Brent Group deposition, rather than through groundwater circulation during the Kimmerian tectonic phase.     

Order acceptance with weighted tardiness

Over the past decade the strategic importance of order acceptance has been widely recognized in practice as well as academic research. This paper examines order acceptance decisions when capacity is limited, customers receive a discount for late delivery, but early delivery is neither penalized nor rewarded. We model a manufacturing facility that considers a pool of orders, and chooses for processing the subset that results in the highest profit. We present several solution methods, beginning with a straightforward application of an approach which separates sequencing and job acceptance. We then develop an optimal branch-and-bound procedure that uses a linear (integer) relaxation for bounding and performs the sequencing and job acceptance decisions jointly. We develop a variety of fast and high-quality heuristics based on this approach. For small problems, beam search runs almost 20 times faster than the benchmark, with a high degree of accuracy, and a branch-and-bound heuristic using Vogel's method for bounding is over 100 times faster with very high accuracy. For larger problems, a myopic heuristic based on the relaxation runs 2000 times faster than the beam-search benchmark, with comparable accuracy.