The localization model of rubber elasticity and the stress-strain behavior of a network formed by cross-linking a deformed melt

This paper examines the copolymerzation of methyl acrylate (MA) and isobutylene (IB) with a complexed initiating system of AlEtCl₂ and benzoyl peroxide (BPO). The effects of monomer ratio, monomer concentration, initiator composition and polymerization conditions on copolymer composition, degree of alternation, intrinsic viscosity and conversion were studied. An alternating copolymer was obtained when the [IB] / [MA] mole ratio was equal or greater than one.     

Three-dimensional converging-diverging Gaussian beam diffraction by a volume grating

The diffraction characteristics of a volume grating (VG) illuminated by a three-dimensional (3-D) converging-diverging Gaussian beam at conical incidence are investigated by applying 3-D finite-beam (FB) rigorous coupled-wave analysis (RCWA) based on the conventional 3-D RCWA in conjunction with two-dimensional plane-wave decomposition. The Gaussian beam is assumed to have an arbitrary incidence angle, an arbitrary azimuthal angle, and any linear polarization. The two cases with linear polarizations of the central beam of the Gaussian (E perpendicular K and H perpendicular K) are investigated. The diffraction efficiencies and the diffracted beam profiles for both unslanted VGs and slanted VGs (designed for substrate-mode optical interconnects) are presented. In general, the diffraction efficiencies of a converging-diverging spherical Gaussian beam diffracted by both unslanted VGs and slanted VGs increase and approach the central-beam results as the refractive-index modulation increases.     

Optimization of finite-length input volume holographic grating couplers illuminated by finite-width incident beams

A finite volume holographic grating coupler (VHGC) normally illuminated with various incident-beam profiles (such as a Gaussian beam, a flat cosine-squared beam, and an exponential-decay beam) with finite beam widths for input coupling is rigorously analyzed by use of the finite-difference frequency-domain method. The effects of the incident-beam width, the incident-beam position, the incident-beam profile, and the incident-beam angle of incidence on the input coupling efficiency are investigated. The optimum conditions for input coupling are determined. Both a VHGC embedded in the waveguide film region and a VHGC placed in the waveguide cover region are investigated. For a given finite VHGC, the input coupling efficiencies are strongly dependent on incident-beam widths, incident-beam positions, and incident-beam angles of incidence, but are only weakly dependent on incident-beam profiles.     

Animal models of psychopathology: The low-norepinephrine and low-serotonin rat.

A variety of evidence implies that alterations in the midbrain neuronal systems that use the monamines norepinephrine and serotonin as transmitters are involved in emotional imbalances and psychopathology in humans. The effects of alterations in these circuits can be studied in animals administered selective monoamine neurotoxins. From 7 yrs of research on the effects of alterations in norepinephrine and serotonin on rat behavior, the author notes that rats with norepinephrine depletions are inactive, have hunger deficits, and model aspects of depression, while rats with serotonin depletions are hyperactive, are frightened in novel environments, and model aspects of anxiety. When kept in isolation cages following lesioning, these animals recover but develop paradoxical, overcompensatory behavioral syndromes. When allowed to recover in social rat-colony environments, these animals become progressively more similar to controls, but their presence in the social colony leads to gradually increasing social disruptions. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Guided-mode resonant subwavelength gratings: effects of finite beams and finite gratings

The effects of finite beams and finite gratings on the performance of guided-mode resonant subwavelength gratings are characterized by using the rigorous boundary element method. The gratings are strongly modulated, have a finite number of periods, and are illuminated by normally incident Gaussian beams. Quantitative results are presented for silicon-on-sapphire resonant gratings and gallium arsenide-aluminum arsenide resonant gratings.     

Algorithm performance in the determination of the refractive-index profile of optical fibers

Three algorithms for computing the refractive-index profile of azimuthally symmetric optical fibers via the inverse Abel transform are compared to determine their relative accuracies. Appropriate values of algorithm parameters are also determined. The direct differentiation algorithm, the iterative algorithm, and the Fourier algorithm are used to calculate the refractive-index profile from simulated measurements of the phase shift of light transmitted transversely through the fiber. The rms error in the calculated index profile is used to quantify the accuracy of each algorithm. The Fourier algorithm is typically the most accurate of the three.     

Electric field, permittivity, and strain distributions induced by interdigitated electrodes on electrooptic waveguides

Integrated optical interdigitated-electrode devices are used to diffract light and to launch acoustic waves. The electric field and the permittivity and strain tensors induced by a voltage applied to periodic interdigitated electrodes of finite thickness on the surface of an anisotropic electrooptic crystalline waveguide are calculated rigorously. A buffer layer between the electrodes and the waveguide is included in the analysis.     

Child witnesses to domestic violence: A meta-analytic review.

This meta-analysis examined 118 studies of the psychosocial outcomes of children exposed to interparental violence. Correlational studies showed a significant association between exposure and child problems (d? = -0.29). Group comparison studies showed that witnesses had significantly worse outcomes relative to nonwitnesses (d? = -0.40) and children from verbally aggressive homes (d? = -0.28), but witnesses' outcomes were not significantly different from those of physically abused children (d? = 0.15) or physically abused witnesses (d? = 0.13). Several methodological variables moderated these results. Similar effects were found across a range of outcomes, with slight evidence for greater risk among preschoolers. Recommendations for future research are made, taking into account practical and theoretical issues in this area. (PsycINFO Database Record (c) 2010 APA, all rights reserved)