Laser-machined piezoelectric cantilevers for mechanical energy harvesting

In this study, we report results on a piezoelectric- material-based mechanical energy-harvesting device that was fabricated by combining laser machining with microelectronics packaging technology. It was found that the laser-machining process did not have significant effect on the electrical properties of piezoelectric material. The fabricated device was tested in the low-frequency regime of 50 to 1000 Hz at constant force of 8 g (where g = 9.8 m/s(2)). The device was found to generate continuous power of 1.13 microW at 870 Hz across a 288.5 kOmega load with a power density of 301.3 microW/cm(3).     

Near- and Far-Field Characterization of Planar mm-Wave Antenna Arrays with Waveguide-to-Microstrip Transition

We present the design and characterization of planar mm-wave patch antenna arrays with waveguide-to-microstrip transition using both near- and far-field methods. The arrays were designed for metrological assessment of error sources in antenna measurement. One antenna was designed for the automotive radar frequency range at 77 GHz, while another was designed for the frequency of 94 GHz, which is used, e.g., for imaging radar applications. In addition to the antennas, a simple transition from rectangular waveguide WR-10 to planar microstrip line on Rogers 3003? substrate has been designed based on probe coupling. For determination of the far-field radiation pattern of the antennas, we compare results from two different measurement methods to simulations. Both a far-field antenna measurement system and a planar near-field scanner with near-to-far-field transformation were used to determine the antenna diagrams. The fabricated antennas achieve a good matching and a good agreement between measured and simulated antenna diagrams. The results also show that the far-field scanner achieves more accurate measurement results with regard to simulations than the near-field scanner. The far-field antenna scanning system is built for metrological assessment and antenna calibration. The antennas are the first which were designed to be tested with the measurement system.     

Fexofenadine/cyclodextrin inclusion complexation: phase solubility, thermodynamic, physicochemical, and computational analysis

Interactions of fexofenadine (Fexo) with cyclodextrins (CDs: alpha- beta-, gamma-, and HP-beta-CD) were investigated by several techniques including phase solubility, differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), (1)H-nuclear magnetic resonance ((1)H-NMR) and molecular mechanical modeling (MM(+)). The effects of CD type, pH, ionic strength, and temperature on complex stability were also explored. Fexo/CD complex formation follows the decreasing order: beta-CD > HP-beta-CD > gamma-CD > alpha-CD (i.e., at pH 7.0 and 30 degrees C, K(11) = 1139, 406, 130, and 104 M(-1), respectively). The linear correlation of the free energy of Fexo/beta-CD complex formation (DeltaG(11)) with the free energy of inherent Fexo solubility (DeltaG(So)), obtained from the variation of K(11) with inherent Fexo solubility (S(o)) at different pHs and ionic strengths, was used to measure the contribution of the hydrophobic character of Fexo to escape from water by including into the hydrophobic CD cavity. The hydrophobic effect (desolvation) contributes about 76% of the total driving force towards inclusion complex formation, while specific interactions contribute -7.7 kJ/mol. Moreover, Zwitterionic Fexo/beta-CD complex formation appears to be driven both by favorable enthalpy (DeltaH degrees = -23.2 kJ/mol) and entropy (DeltaS degrees = 15.2 J/molxK) changes at pH 7.0. (1)H-NMR and MM(+) studies indicate multimodal inclusion of the piperidine, carboxypropylphenyl, and phenyl moieties into the beta-CD cavity. MM(+) computations indicate that the dominant driving force for complexation is Van der Waals force with very little electrostatic contribution. (1)H-NMR, DSC, and XRPD studies indicate the formation of inclusion complex in aqueous solution and the solid state.     

Numerical chromosomal abnormalities detected by atomic force microscopy.

The numerical abnormalities of human metaphase chromosomes, fixed according to standard procedures for optical microscopy but not treated for banding, were detected by atomic force microscopy (AFM). High-resolution AFM imaging of chromosomes in trisomy 13, 21, and Klinefelter syndrome can be compared directly with the traditional optical image. The unbanded metaphase chromosomes, including the extra ones in trisomic patients showed a structural pattern very similar to G-banding. Comparison of AFM images with light microscopic data allows the identification of specific chromosomes, and images of chromosomes showing numerical and structural abnormalities can then be analysed.     

Performance‐based evaluations of the tangible benefits of information networks with applications

This paper provides a new methodology for the evaluation of the tangible benefits of information networks, based on their utilization and performance. The methodology enables the evaluation of different tangible benefits including those resulting from time, movement, paper, and space savings. Copyright © 2000 John Wiley & Sons, Ltd.     

Computer simulation for the evaluation of static and dynamic priority schemes in an ATM multiplexer with multimedia traffic

This paper is concerned with the evaluation of static and dynamic priority schemes for ATM multiplexers using digital computer simulation and has three main parts. The first provides a basic computer simulation model of an ATM multiplexer with multimedia traffic streams that enables investigation of static and dynamic priority schemes. The second part uses the simulation model to study such schemes. The third part investigates combined dynamic space and dynamic time priorities to provide better performance for ATM multiplexers in comparison to using dynamic time priority only. Copyright © 1999 John Wiley & Sons, Ltd.     

Effect of upper shielding and conductor backing on quasistatic parameters of asymmetric coplanar waveguides

CAD‐oriented analytic formulas are presented for calculating the quasistatic parameters of the conductor‐backed asymmetric coplanar waveguide (ACPW), the ACPW with upper shielding, and the conductor‐backed ACPW with upper shielding using conformal mapping techniques. The effect of the presence of the upper shielding and the conductor‐backing on the quasistatic TEM parameters is discussed. It is also presented that the expressions derived in this work can be used for calculating the quasistatic parameters of various symmetric and asymmetric CPWs. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 394–402, 1999     

Analysis of the cost‐effectiveness of information networks with applications

This paper presents a methodology for the analysis of the cost‐effectiveness of information networks over a period of time. The cost‐effectiveness is considered to be associated with use‐dependent and use‐independent costs and benefits. Copyright © 2000 John Wiley & Sons, Ltd.     

Ordered Semantic Hyper Tableaux

A family of tableau methods, called ordered semantic hyper (OSH) tableau methods for first-order theories with function symbols, is presented. These methods permit semantic information to guide the search for a proof. They also may make use of orderings on literals, clauses, and interpretations to guide the search. In a typical tableau, the branches represent conjunctions of literals, and the tableau represents the disjunction of the branches. An OSH tableau is as usual except that each branch B has an interpretation I ₀[B] associated with it, where I ₀ is an interpretation supplied at the beginning and I ₀[B] is the interpretation most like I ₀ that satisfies B. Only clauses that I ₀[B] falsifies may be used to expand the branch B, thus restricting the kinds of tableau that can be constructed. This restriction guarantees the goal sensitivity of these methods if I ₀ is properly chosen. Certain choices of I ₀ may produce a purely bottom-up tableau construction, while others may result in goal-oriented evaluation for a given query. The choices of which branch is selected for expansion and which clause is used to expand this branch are examined and their effects on the OSH tableau methods considered. A branch reordering method is also studied, as well as a branch pruning technique called complement modification, that adds additional literals to branches in a soundness-preserving manner. All members of the family of OSH tableaux are shown to be sound, complete, and proof convergent for refutations. Proof convergence means that any allowable sequence of operations will eventually find a proof, if one exists. OSH tableaux are powerful enough to be treated as a generalization of several classes of tableau discussed in the literature, including forward chaining and backward chaining procedures. Therefore, they can be used for efficient query processing.