CAS-BUS: A Test Access Mechanism and a Toolbox Environment for Core-Based System Chip Testing

As System on a Chip (SoC) testing faces new challenges, some new test architectures must be developed. This paper describes a Test Access Mechanism (TAM) named CAS-BUS that solves some of the new problems the test industry has to deal with. This TAM is scalable, flexible and dynamically reconfigurable. The CAS-BUS architecture is compatible with the IEEE P1500 standard proposal in its current state of development, and is controlled by Boundary Scan features.This basic CAS-BUS architecture has been extended with two independent variants. The first extension has been designed in order to manage SoC made up with both wrapped cores and non wrapped cores with Boundray Scan features. The second deals with a test pin expansion method in order to solve the I/O bandwidth problem. The proposed solution is based on a new compression/decompression mechanism which provides significant results in case of non correlated test patterns processing. This solution avoids TAM performance degradation.These test architectures are based on the CAS-BUS TAM and allow trade-offs to optimize both test time and area overhead. A tool-box environment is provided, in order to automatically generate the needed component to build the chosen SoC test architecture.     

Parametric simulation and performance analysis of a solar gas turbine power plant from thermodynamic and exergy perspectives

Using solar energy in gas turbine cycles is a new method that can improves the efficiency of gas turbines. Placing a solar receiver before a combustion chamber can raise the temperature of the air coming into the chamber and reduce the consumption of fuel in the chamber. The system that combines a solar energy receiver with a gas turbine cycle is technically called a “solar gas turbine”. The goal of this paper is the parametric simulation and performance analysis of a gas turbine cycle equipped with a solar receiver from thermodynamic and exergy aspects of view. The selected parameters in this study, include the pressure ratio of compressor, the temperature of gases at the turbine inlet and the direct normal irradiance. The obtained results indicate that the fuel consumption of this combined system is reduced by using a solar receiver and the temperature of gases entering the combustion chamber increased. The reduction of consumed fuel, in turn, reduces the rate of exergy destruction in the combustion chamber. Another important point is that the solar receiver itself has the least amount of exergy destruction. The net power generated by a solar gas turbine cycle is 10 % higher than that produced by a simple gas turbine cycle. Also, the studies show that the electrical efficiency of a solar gas turbine cycle is about 41 % higher than the simple gas turbine cycle.

     

On the modeling of tilted fixed-guided flexible beams under tension

We derive explicit solutions for a fixed-guided slender suspension beam that is initially straight and tilted with respect to the moving direction of its sliding end. The beam experiences substantial axial forces during the tension, resulting in a nonlinear boundary value problem. We consider sliding end displacements in the direction that cause longitudinal tension along the beam. We first propose an exact approach, leading to analytical solutions for various physical variables such as the transverse force and deflection profile, in terms of the axial force and the positive real solution of a third-order algebraic equation. We also propose an alternative approximate solution based on a second-order equation, which provides closed-form analytical solutions for the physical variables. We also introduce analytical validation techniques for the underlying assumptions. Consistency with nonlinear finite-element analysis is also addressed. Moreover, the results of the approximate method are represented by dimensionless formulas, generating charts to predict solutions for arbitrarily assigned beam parameters. Magnitudes of the normal and shear stress values are also included to consider the effects of yield and shear strengths as the limiting factors at large deflection conditions.     

Study of Reaction Between Slag and Carbonaceous Materials

The chemical interaction of a typical slag of EAF with three different carbon sources, coke, rubber-derived carbon (RDC), coke-RDC blend, was studied in atmospheric pressure at 1823 K (1550 °C). Using an IR-gas analyzer, off-gases evolved from the sample were monitored. While the coke-RDC blend exhibited the best reducing performance in reaction with molten slag, the RDC sample showed poor interaction with the molten slag. The gasification of the coke, RDC, and coke-RDC blend was also carried out under oxidizing conditions using a gas mixture of CO₂ (4 wt pct) and Ar (96 wt pct) and it was shown that the RDC sample had the highest rate of gasification step \( C_{0} \mathop{\longrightarrow}\limits{{k_{3} }}{\text{CO}} + nC_{\text{f}} \) (11.6 site/g s (×6.023 × 10²³/2.24 × 10⁴)). This may be attributed to its disordered structure confirmed by Raman spectra and its nano-particle morphology observed by FE-SEM. The high reactivity of RDC with CO₂ provided evidence that the Boudouard reaction was fast during the interaction with molten slag. However, low reduction rate of iron oxide from slag with RDC can be attributed to the initial weak contact between RDC and molten slag implying that the contact between carbonaceous matter and slag plays significant roles in the reduction of iron oxide from slag.     

Performance enhancement of PEMC liquid level sensor subjected to environmental temperature variation

In this paper, the performance of a resonant Piezoelectric-excited Millimeter-sized Cantilever (PEMC) used as liquid level sensor has been studied. The sensitivity of this sensor affected by environmental temperature variation is investigated via theoretical and Finite Element Models (FEM). In order to validate this FEM, first, simulation results are compared with the theoretical and experimental ones for a sensor operating at constant room temperature. The simulation results are in a good agreement with experimental ones. Then, proposed theoretical model and FEM are used to study the dynamic behavior of the device when the environmental temperature is changed. The results indicate that although natural frequencies of sensor change due to temperature variation, the resultant shift remains almost the same regardless of specific immersion depths. Also, it can be concluded that temperature variation of about 50 °C affects the liquid level measurement accuracy up to 29 μm which is significant compared to a minimum detectable liquid level change of about 8 μm by this sensor reported previously in literature.     

Effect of thermal and mechanical properties variations on microcantilever mass sensor performance

Ensuring desirable performance for piezoelectric microcantilever sensors constitutes a crucial research subject particularly for the applications such as detection of biochemical entities, virus particles or human biomarkers. However, these sensors’ performance may be affected by the environmental conditions such as temperature variation, and/or the uncertainty in the material properties. The objective of this study is to explore Young modulus uncertainty of microcantilever’s structural layer, thermo-mechanical and geometrical temperature dependency effects, on the natural frequency, bias and sensitivity of microcantilever mass sensors. These effects have been investigated for different sensor lengths and resonant modes. Also, a temperature compensation method which omits the need for bulky non-contact thermometers or fabrication of built-in temperature sensor has been proposed. As theoretical model, Euler–Bernoulli beam theory has been employed and solved by Galerkin expansion procedure. Using this model, it is demonstrated that the sensitivity of microcantilever sensor decreases with increasing the added mass. The microcantilever sensor sensitivity operating at the second resonant mode has been improved almost five times comparing to the first mode sensitivity regardless of microcantilever length. The simulation results show that temperature variation causes thermal frequency shift which in turn introduces a significant mass bias far beyond the sensors’ minimum detectable mass. This mass bias is constant for a given microcantilever in its first and second resonant mode. Additionally, the effect of temperature variation on the sensitivity of the given mass sensors is negligible. However, it has been shown that the variations in sensors sensitivity due to uncertainty of Young modulus remain constant for different lengths and two resonant modes of the microcantilever sensor.     

Buckling of a functionally graded coated solid subjected to sliding contact loading

This paper investigates the buckling of a bi-layered material with functionally graded coating including a pre-existing interface crack. In order to investigate this phenomenon which is of particular interest to the tribological community, the stresses due to sliding cylindrical loading were determined. Solutions for stresses are obtained by use of Fourier transform technique. These stress fields under such loading are strongly affected by various parameters such as friction coefficient, indenter tip radius, film thickness, etc. Therefore, to assess the coating strength reliably, the mechanical stress field developed by mixed normal and tangential surface pressure was analyzed by considering the affected parameters. The mechanical properties of the FG coating are assumed to vary exponentially through the thickness. On the basis of stress analysis, a satisfactory framework was developed to study the buckling of FG coatings. An interface crack was assumed to model the actually occurring flaws in such coated systems, and the critical buckling stress was obtained.     

Optimal design analysis of electrothermally driven microactuators

This paper explores a comparative study between different designs of electrothermal microactuators with emphasis on optimal design and performance key factors. For this purpose, two typical designs for electrothermal microactuators with the same material properties are studied: one with different beam lengths (design A), other one with different beam sections and a flexure part (design B). Analytical model and finite element model (FEM) have been developed and validated by comparison of simulation results with experimental results in literature. Optimal geometrical dimensions to achieve maximum deflection have been obtained using genetic algorithm (GA). As the key factors, temperature distribution, power consumption and deflection of these microactuators have been compared in the range of microactuator functionality. Design B is more sensitive to geometrical dimension variation. Using optimal geometrical dimensions, an increase of almost 40 and 55% has been achieved for design A and B tip deflections, respectively. The modified design A with a gold layer results to an increase of 70% for tip deflection comparing to its optimal design.     

Transparent and Flexible Mn1−x−y(CexLay)O2−δ Ultrathin-Film Device for Highly-Stable Pseudocapacitance Application

Control over the fabrication of state-of-the-art portable pseudocapacitors with the desired transparency, mechanical flexibility, capacitance, and durability is challenging, but if resolved will have fundamental implications. Here, defect-rich Mn_1−x−y(Ce_xLa_y)O_2−δ ultrathin films with controllable thicknesses (5–627 nm) and transmittance (≈29–100%) are fabricated via an electrochemical chronoamperometric deposition using a aqueous precursor derived from end-of-life nickel-metal hydride batteries. Due to percolation impacts on the optoelectronic properties of ultrathin films, a representative Mn_1−x−y(Ce_xLa_y)O_2−δ film with 86% transmittance exhibits an outstanding areal capacitance of 3.4 mF cm⁻², mainly attributed to the intercalation/de-intercalation of anionic O²⁻ through the atomic tunnels of the stratified Mn_1−x−y(Ce_xLa_y)O_2−δ crystallites. Furthermore, the Mn_1−x−y(Ce_xLa_y)O_2−δ thin-film device exhibits excellent capacitance retention of ≈90% after 16 000 cycles. Such stability is associated with intervalence charge transfer occurring among interstitial Ce/La cations and Mn oxidation states within the Mn_1−x−y(Ce_xLa_y)O_2−δ structure. The energy and power densities of the transparent flexible Mn_1−x−y(Ce_xLa_y)O_2−δ full-cell pseudocapacitor device, is measured to be 0.088 μWh cm⁻² and 843 µW cm⁻², respectively. These values show insignificant changes under vigorous twisting and bending to 45–180° confirming these value-added materials are intriguing alternatives for size-sensitive energy storage devices.