Modular Functionalization of Electrodes by Cross‐Coupling Reactions at Their Surfaces

Due to the increasing importance of modified electrodes for many applications in nanotechnology, including molecular electronics, bioelectronics, and sensors, there is a need to find ways to chemically attach suitable molecular films onto the electrodes. Combining the electroreduction of aryl diazonium salts with the Sonogashira cross‐coupling reaction, a new modular technique to modify electrodes is presented. The new technique allows a wide range of functional groups to be introduced onto electrode surfaces with high surface coverage by the functional subunit. Various organic subunits, including redox chromophores, are successfully attached to platinum electrodes. The corresponding films are characterized using cyclic voltammetry, X‐ray photoelectron spectroscopy, atomic force microscopy, and contact‐angle measurements. The electroreduction of diazonium salts is successfully achieved on a broad variety of conducting and semiconducting surfaces, which shows that the technique is applicable to a broad variety of substrates.     

On the recovery of the time average of continuous and discrete time functions from their Laplace and z‐transforms

The determination of the time averages of continuous functions or discrete time sequences is important for various problems in physics and engineering, and the generalized final‐value theorems of the Laplace and z‐transforms, relevant to functions and sequences not having a limit at infinity, but having a well‐defined average, can be very helpful in this determination. In the present contribution, we complete the proofs of these theorems and extend them to more general time functions and sequences. Besides formal proofs, some simple examples and heuristic and pedagogical comments on the physical nature of the limiting processes defining the averaging are given. Copyright © 2012 John Wiley & Sons, Ltd.     

Strategies of therapeutic intervention—classification by restraining and driving forces.

Presents the conceptual framework for a new method of classification of strategies of therapeutic intervention. The classification is based on the terms driving force and restraining force, where a driving force operates in the direction of achieving the therapeutic aim and a restraining force operates against this direction. Seven strategies are identified, and each is illustrated by an example from the literature. The seven strategies are (a) enhancing the driving forces, (b) reducing the restraining forces, (c) preventing the driving forces from reducing each other's effects, (d) preventing the restraining forces from enhancing each other's effects, (e) causing the driving forces to enhance each other's effects, (f) causing the restraining forces to reduce each other's effects, and (g) transforming the restraining forces into driving forces. The theoretical and practical value of the classification is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A multiple objective grouping genetic algorithm for assembly line design

The purpose of this paper is to describe some of the main problems concerning assembly line design. The focus will be on the following steps: (1) the input data preparation, (2) the elaboration of the logical layout of the line, which consists in the distribution of operations among stations along the line and an assignment of resources to the different stations, (3) finally the mapping phase using a simulation package to check the obtained results. This work presents a new method to tackle the hybrid assembly line design, dealing with multiple objectives. The goal is to minimize the total cost of the line by integrating design (station space, cost, etc.) and operation issues (cycle time, precedence constraints, availability, etc.). This paper also presents in detail a very promising approach to solve multiple objective problems. It is a multiple objective grouping genetic algorithm hybridized with the multicriteria decision-aid method PROMETHEE II. An approach to deal with users preferences in design problems is also introduced. The essential concepts adopted by the method are described and its application to an industrial case study is presented.     

Current Harmonics Measurement by Means of Current Transformers

This paper analyzes the accuracy of current transformers (CT) when excited with nonsinusoidal currents. It uses a nonlinear model that accounts for the minor hysteresis loop of the core. It was concluded that instrument transformers with accuracy class 0.6 or better provide reasonably accurate measurements of current harmonics magnitudes, however the phase angle error may lead to unacceptable errors when the current transformers are used to measure active powers. If such measurements are used to determine the power flow direction, i.e., if a load or consumer pollutes or is polluted, even high accuracy class CTs may yield unsatisfactory results.     

Calculations and hypotheses relating to the input conductivity function of an infinite grid of similar nonlinear resistors

A formula for the input conductivity characteristic of an infinite grid of similar, weakly nonlinear resistors (conductors) measured between two nodes is obtained using a specific approximate representation of the grid. This formula is more precise than the corresponding formula given earlier by Gluskin. Some hypotheses concerning the analytical features of the input resistive (conductive) function, not necessarily associated with weak nonlinearity, and also related to circuits of other topologies, are considered. One of the hypotheses leads to a simplified method of calculation of the input conductivity, which has a reasonable engineering precision and may replace incomparably more difficult calculations. The derivations are given in detail.     

Operational Considerations for Teaming Manned and Unmanned Helicopter

“Manned-Unmanned Teaming” among others refers to the use of an unmanned, flying sensor. One use for this is as an integral part of air units’ flying systems. Secondly, it can be used as an independent, recessed robotic component during missions, even from far away and ahead of time. As part of the German R&T project “Manned- Unmanned Teaming” (MUM-T), Elektroniksystem- und Logistik-GmbH (ESG) was assigned the task of investigating these concepts and the options for their realization. The focus of the investigation was initial operation capability within a narrow time frame concentrating on German Army Aviation helicopters. The paper focuses on the results achieved by ESG and begins with a short project overview. In the main part a representative MUM-T mission based on a personnel recovery mission is presented. The mission was demonstrated by ESG in close cooperation with German Army Aviation Combat Development Division (Ger AAV CDD). Beside operational aspects, technical aspects will be discussed. The lecture will close with a short outlook on the next steps, bringing MUM-T missions into service.     

Microstructural characterization and in vitro bioactivity of porous glass-ceramic scaffolds for bone regeneration by synchrotron radiation X-ray microtomography

One of the key purposes of bone tissue engineering is the development of new biomaterials that can stimulate the body's own regenerative mechanism for patient's anatomical and functional recovery. Bioactive glasses, due to their versatile properties, are excellent candidates to fabricate porous 3-D architectures for bone replacement. In this work, morphological and structural investigations are carried out on Bioglass^®- and CEL2-derived scaffolds produced by sponge replication (CEL2 is an experimental glass developed at Politecnico di Torino). Synchrotron radiation X-ray microtomography is used to study the samples 3-D architecture, pores size, shape, distribution and interconnectivity, as well as the growth kinetics on scaffolds struts of a newly formed apatitic phase during in vitro treatment in simulated body fluid, in order to describe from a quantitative viewpoint the bioactive potential of the analyzed biomaterials. An accurate comparison between architectural features and bioactive behaviour of Bioglass^®- and CEL2-derived scaffolds is presented and discussed.     

Integral transform solution for hyperbolic heat conduction in a finite slab

An analytical integral transformation of the thermal wave propagation problem in a finite slab is obtained through the generalized integral transform technique (GITT). The use of the GITT approach in the analysis of the hyperbolic heat conduction equation leads to a coupled system of second order ordinary differential equations in the time variable. The resulting transformed ODE system is then numerically solved by Gear's method for stiff initial value problems. Numerical results are presented for the local and average temperatures with different Biot numbers and dimensionless thermal relaxation times, permitting a critical evaluation of the technique performance. A comparison is also performed with previously reported results in the literature for special cases and with those produced through the application of the Laplace transform method (LTM), and the finite volume-Gear method (FVGM).     

Superresolution algorithms for spatial extended scattering centers

Scattering centers model (SCM) is usually considered for modeling target backscattered signal in high-resolution radar. In this case the impulse response of each scattering center is represented by a time-delayed Dirac pulse. Some of most popular superresolution imagery techniques, such as MUSIC or ESPRIT, are well-matched to this model. Under this hypothesis, they outperform Fourier-based techniques in terms of both spatial and dynamic resolutions. However, the behavior of real-world targets is often very different from that of the SCM. Indeed, their reflectivity function is not confined just to several perfectly localized scattering centers, but it can be rather approximated by a set of scattering regions having different spatial extent. SCM becomes then inappropriate and the superresolution methods may provide unexpected results. Furthermore, the amplitude information is difficult to interpret in this case. In this paper we propose an extension of two superresolution methods, MUSIC and ESPRIT, to cope with extended scattering centers (ESC). According to this model, the impulse response of an ESC is not a Dirac pulse, but a window of finite support. Besides the position, the size (spatial extent) of this window is also recovered. This additional information about the target structure can be used for increasing ATR (automatic target recognition) accuracy and robustness.