Penny-shaped crack in a transversely isotropic solid

An analytical solution is given for the displacement and stress distribution produced in the interior of a transversely isotropie solid containing a penny-shaped crack situated in an elastic symmetry plane and axially-loaded. Curves of numerical results are presented for the stress intensity factor and the normal displacement. They show the influence of this type of anisotropy.     

Combined, but not single, gustatory nerve transection substantially alters taste-guided licking behavior to quinine in rats.

On the basis of electrophysiological studies, the glossopharyngeal nerve (GL) is far more responsive to quinine than the chorda tympani (CTP) or greater superficial petrosal (GSP) nerves. The licking behavior of 72 male, water-deprived rats to quinine (0.03–3.0 mM) and distilled water (10-sec trials) was tested before and after various nerve transections. GL?+?CTP section caused a substantial reduction in responsiveness. GSP?+?CTP section had a moderate effect, and GL section alone produced only marginal impairments. Control, partially desalivated, and CTP-sectioned rats were unaffected. Thus, the GL is not necessary for normal unconditioned taste-guided appetitive responsiveness to quinine, but the collective input from the GSP and CTP is necessary and most likely sufficient. These data suggest that the quinine-evoked input of the GL and CTP converge centrally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analog VLSI for robot path planning

Analog VLSI provides a convenient and high-performance engine for robot path planning. Laplace's equation is a useful formulation of the path-planning problem; however, digital solutions are very expensive. Since high precision is not required, an analog approach is attractive. A resistive network can be used to model the robot's domain with various boundary conditions for the source, target, and obstacles. A gradient descent can then be traced through the network by comparing node voltages. We built two analog CMOS VLSI chips to investigate the feasibility of this technique. Design issues included the choice of resistive element, tessellation of the domain, programming of the network, and readout of the settled network. Both chips can be connected to a standard VME bus interface to permit their use as coprocessors in otherwise digital systems.A preliminary short version of this paper was presented at the 1992 ASILOMAR Conf. on Computers, Signals and Systems.     

Full polarization insensitivity of a 20 Gb/s strained-MQWelectroabsorption modulator

We report on a MQW electroabsorption modulator with tensile-strained wells. The device transmission is shown to be fully polarization insensitive, i.e. both in amplitude and phase. The modulation efficiency is over 20 GHz/V (bandwidth higher than 20 GHz and 1 V drive voltage) which is the highest figure of merit reported for any kind of polarization insensitive modulator. Full polarization independence is further demonstrated by 2.5 Gb/s transmission at 1.55 μm over 475 km of standard fiber without penalty at 10^-9 BER whatever the polarization     

A simulation method for stationary Gaussian random functions based on the sampling theorem

A unified method is developed for simulating realizations of real-valued stationary Gaussian processes, vector processes, fields, and vector fields. The method is based on parametric random models consisting of superpositions of deterministic functions of time or space with random amplitudes. The parametric models are based on the sampling theorem for random processes and generalizations of it for vector processes and random fields. The proposed simulation method is efficient and uses algorithms for generating realizations of random processes and fields that are similar to simulation techniques based on ARMA models. Several examples are presented to demonstrate the proposed simulation method and evaluate its efficiency and accuracy.     

Metalorganic InP and Inx Ga1-x,Asy P1-y,on InP epitaxy at atmospheric pressure

We present a procedure for the MOVPE of InP as simple as the one currently used for GaAs. InP and InGaAsP alloys are grown on InP substrates using trimethy1indium (TMI), phosphine, trimethylgallium (TMG) and arsine. The choice of carrier gas is important ; a mixture of hydrogen and nitrogen allowed us to grow uniform layers over large areas at atmospheric pressure, without pyrolizing the phosphine or separating the input reactants. Preliminary characterization results are presented. Most information contained in this paper was presented at the 1983 Electron Materials Conference as paper Cl.     

Structural Analysis and Testing of HV Busbar Assemblies with Rigid Conductors under Short-Circuit Conditions

A general method is presented for calculating the dynamic stresses and displacements of busbar structures with rigid conductors under various short-circuit conditions, with or without reclosing on a fault. Based on a finite-element technique and modal-response superposition, this method can be used to study a complex busbar structure in its entirety, taking into account both the three-dimensional aspect of the structural components and the paths followed by the fault currents. An explicit solution for the specific modal responses enhances the efficiency of the procedure. Laboratory tests on a three-dimensional busbar model and, also, extensive field tests on the busbars of a 315-kV substation have been performed kinder various fault conditions. The experimentally determined dynamic responses are compared with the finite-element solutions. Specific conclusions are drawn regarding the structural behavior of Hydro-Québec's 315-kV substations. Practical recommendations of general interest for the fault analysis of busbar structures are included.     

InP MIS transistors with grown-in sulphur dielectric

We report the first experimental results on accumulation layer InP MISFETs where the gate dielectric is grown into the substrate by chemical reaction with sulphur. These MIS structures have very little hysteresis and very high transistor transconductances.     

The Effect of the Ionizing Radiation on Hydroxyapatite–Polydimethylsiloxane Layers

The bio hydroxyapatite (HAp) was used from a long time in different medical and environmental applications. The HAp layers with a uniform surface were used for various medical applications such as orthopedic and dental metal implants. In this work, we reported on the influence of X‐ray radiation on the structural and morphological properties of composite layers based on HAp and polydimethylsiloxane (PDMS) deposited on titanium substrates. The HAp:PDMS layers were investigated by different complementary methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and glow discharge optical emission spectrometry (GDOES). FTIR spectral analysis showed that the molecular structure of the coatings was not changed after their irradiation even though, the depth profile analysis performed by GDOES indicated a depletion of Ca and P elements from the HAp:PDMS irradiated samples. By SEM, we showed that the morphological features of the coatings were also changed, as the irradiated layers are delaminated. The biological assays confirmed that the antibacterial activity of HAp:PDMS composite layers increased after irradiation. The results obtained in this study highlighted that the biological properties of HAp:PDMS layers could be influenced by irradiation. POLYM. ENG. SCI., 59:2406–2412, 2019. © 2019 Society of Plastics Engineers