New expressions for depolarization dyadics in uniaxial dielectric-magnetic media

We present some novel expressions for the depolarization dyadics in uniaxial dielectric-magnetic media. These expressions were obtained by generalizing the Fikioris approach for extracting the singular behaviour of integrals involving the dyadic Green functions and the source current density distributions. Cubical, cylindrical and spherical geometries serve as examples for a discussion of the depolarization dyadics' dependence on geometry and anisotropy.     

Thermal and thermoelastic properties of fast extrusion furnace (FEF) carbon black loaded SBR vulcanizates

The effect of FEF carbon black as filler on the thermal capacity c, diffusivity a, and thermal conductivity λ, of styrene butadiene rubber (SBR) composites in the temperature range 300–420 K was studied. The filler strongly increases the thermal diffusivity, whilst strongly decreasing the thermal capacity and the thermal conductivity (except at high FEF content ≥80 phr). The influence of the filler on the thermoelastic behaviour of the same composites was also investigated. It was found that the thermoelastic temperature change (ΔT) increased with carbon black concentration as well as the entropy change per unit extension.     

Recursive simulation models of the semiconductor laser modulationcharacteristics for accurate performance evaluation of coherent opticalCPFSK systems

Modeling of the semiconductor laser nonuniform FM response and residual IM modulation is essential for the computer-aided design of coherent optical communication systems. This paper presents an accurate simulation model, in which the FM and IM responses are represented by recursive digital filters derived directly from measurements. A comparison with previous models of the bibliography reveals the advantages of the current approach. The proposed modeling procedure is applied in the case of a single-electrode DFB laser. This DFB model, in combination with a semi-analytical technique for the evaluation of the error probability, is used to study the influence of the modulation characteristics on the performance of a coherent heterodyne CPFSK system with differential receiver operating at 1 Gb/s. Theoretical and experimental results are in excellent agreement     

An experimental investigation of thick-sample effects in the measurement of directional-hemispherical transmittance of advanced glazing materials

Samples that are thick with respect to the measuring apparatus can pose problems in the measurement of directional-hemispherical transmittance. Due to the lateral displacement of light that these samples induce, traditional small-beam techniques are often no longer applicable. Broad-area irradiation offers a solution to these problems, but, in practice, imperfections in the extent and the uniformity of the irradiation can create errors. This paper reports measurement of the “detector-integrated inscattering function”, which describes the lateral displacement of light, for a number of thick samples over a range of incidence angles. This function is used to determine the minimum area that must be irradiated for an accurate broad-area irradiation transmittance measurement. The errors caused by transverse non-uniformities in the irradiance distributions produced by a state-of-the-art broad-area irradiation spectrophotometer are also reported. Errors caused by transverse irradiation non-uniformities are estimated, and transmittance measurements made with small-area and broad-area irradiation are compared. It is shown that in most cases small-area irradiation transmittance measurements underestimate the transmittance of thick samples due to outscattering, and that broad-area irradiation measurements using state-of-the-art irradiation optics can contain large errors of up to 20%, due to irradiance non-uniformities, particularly at large angles of incidence.     

A transient induction motor model including saturation and deep bareffect

Transient cage induction motor models for use in inverter-fed drives and controllers are reviewed. A simple transient model is presented that includes rotor deep bar effect and magnetic saturation of the magnetising and rotor leakage flux paths. The improved model requires motor details in the form of simple impedance versus frequency characteristics which can be obtained from a variety of external sources. These can range typically from detailed steady-state finite-element solutions to simple experimental measurements. The model is verified experimentally using a 75 kW, 4 pole vector controlled AC motor drive     

Stability of pressurized long inelastic cylinders under radial transverse loads

In the present paper, the structural capacity of relatively thick inelastic steel cylindrical tubes under external or internal pressure and concentrated radial loads is investigated, through a rigorous finite element analysis, as well as using a simplified analytical model. For zero pressure, the tubes exhibit inelastic cross-sectional deformation and are capable of dissipating a significant amount of plastic energy. The energy absorption capacity, as well as the ultimate transverse load, are reduced in the presence of external pressure. The effects of internal pressure are also examined. Results are reported in the form of load-deflection curves for different pressure levels. In addition, collapse envelops showing the interaction of pressure versus radial transverse loads are presented. The conclusions of this study are important for the structural integrity of cylindrical steel tubulars for pipeline and other offshore applications.     

A structured procedure for analysis and design of order pick systems

We present a structured procedure for order pick system (OPS) analysis and design that has been established on literature review and interviews with and presentations to OPS experts. In particular, we attempt to include the thinking processes that occur between OPS designers and owners. The design procedure and related issues are discussed in the order of input, selection, and evaluation stages.     

A new protocol for training severely impaired patients in the usage of memory journals

Although memory disorders are frequently seen in survivors of brain injuries, remediation of patients with severe memory disorders is still relatively neglected in clinical practice due to pessimism by clinicians regarding the efficacy of such remediation. With respect to memory journal training, a further reason for this neglect is likely the lack of readily accessible protocols that therapists can use to work with these patients. The purpose of the present paper is to describe a new memory journal training protocol that was developed to teach brain injury survivors how to compensate for severe memory impairments by using three strengths of most brain injury survivors: immediate attention, procedural memory, and old learning. A training protocol is described that involves baseline testing and a needs assessment, five levels of training exercises, and discharge probe testing. It is concluded that patients with severely impaired memory abilities can learn the present system when care is taken to individualize journals, conduct proper needs assessments, and provide structured training exercises geared to the strengths of memory impaired persons.     

Failure analysis of ULSI circuits using photon emission

A real-time failure analysis technique for ULSI circuits using photon emission is proposed. This technique utilizes a photon detection system combined with a circuit tester. Improved failure detection is achieved because the tester can bias arbitrary blocks in the ULSI chip. Detecting and correct process defects and design errors improves the reliability of the ULSI chip