A quasi-static analysis for a class of induced-current EIT systems using discrete coils

A discrete coil EIT system is investigated for the general case of an eccentric circular inhomogeneity. The solution methodology of the forward problem of this system is explained. An optimization procedure using this forward problem solution is developed to find optimum currents that maximize the distinguishability. For an eccentric inhomogeneity problem, it is shown that the coil currents can be optimized to focus the current density in a region of interest. Optimum coil currents under limited peak coil currents constraint and limited total power constraint are obtained. Representative examples that demonstrate the performance of the system are presented.     

Universal product design involving elderly users: a participatory design model

Recent studies have shown that people prefer to age in their familiar environments, thus guiding designers to provide a safe and functionally appropriate environment for ageing people, regardless of their physical conditions or limitations. Therefore, a participatory design model is proposed where human beings can improve their quality of life by promoting independence, as well as safety, useability and attractiveness of the residence. Brainstorming, scenario building, unstructured interviews, sketching and videotaping are used as techniques in the participatory design sessions. Quality deployment matrices are employed to find the relationships between the elderly user's requirements and design specifications. A case study was devised to apply and test the conceptual model phase of the proposed model.     

Product design, semantics and emotional response

This paper explores theoretical issues in ergonomics related to semantics and the emotional content of design. The aim is to find answers to the following questions: how to design products triggering "happiness" in one's mind; which product attributes help in the communication of positive emotions; and finally, how to evoke such emotions through a product. In other words, this is an investigation of the "meaning" that could be designed into a product in order to "communicate" with the user at an emotional level. A literature survey of recent design trends, based on selected examples of product designs and semantic applications to design, including the results of recent design awards, was carried out in order to determine the common attributes of their design language. A review of Good Design Award winning products that are said to convey and/or evoke emotions in the users has been done in order to define good design criteria. These criteria have been discussed in relation to user emotional responses and a selection of these has been given as examples.     

Plasma polymerization‐modified bacterial polyhydroxybutyrate nanofibrillar scaffolds

The design and the development of novel scaffold materials for tissue engineering have attracted much interest in recent years. Especially, the prepared nanofibrillar scaffold materials from biocompatible and biodegradable polymers by electrospinning are promising materials to be used in biomedical applications. In this study, we propose to produce low‐cost and cell‐friendly bacterial electrospun PHB polymeric scaffolds by using Alcaligenes eutrophus DSM 545 strain to PHB production. The produced PHB was characterized by Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Nanofibrous scaffolds were fabricated via electrospinning method that has a fiber diameter approximately 700–800 nm. To investigate cell attachment, cell growth, and antioxidant enzyme activity on positively and negatively charged PHB scaffold, PHB surface was modified by plasma polymerization technique using polyethylene glycol (PEG) and ethylenediamine (EDA). According to the results of superoxide dismutase (SOD) activity study, PEG‐modified nanofibrillar scaffolds indicated more cellular resistance against oxidative stress compared to the EDA modification. As can be seen in cell proliferation results, EDA modification enhanced the cell proliferation more than PEG modification, while PEG modification is better as compared with nonmodified scaffolds. In general, through plasma polymerization technique, surface modified nanofibrillar structures are effective substrates for cell attachment and outgrowth. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

One-stage hypospadias repair with stent or suprapubic diversion: which is better?

PURPOSE: The authors report on 105 consecutive patients who underwent one-stage hypospadias repair based on use of suprapubic diversion or transurethral drainage with stenting. METHODS: The surgical procedures included 52 metal-based flap urethroplasty (Mathieu) for coronal, subcoronal, and distal shaft hypospadias; 32 transverse island pedicle graft (Duckett) for mid and proximal shaft hypospadias; 21 transverse island pedicle (Duckett) plus rolled midline tube (Thierchs) for penoscrotal and scrotal hypospadias. To accomplish urinary drainage, suprapubic diversion (cystofix) was used in 28 of 52 Mathieu operations, in 17 of 32 Duckett operations, and in 11 of 21 transverse island pedicle graft plus rolled midline tube operations. In the rest of the cases, transurethral drainage with stenting was used. RESULTS: All children had excellent cosmetic and functional outcomes. But the rates of complications such as fistula and meatal stenosis were significantly different between the groups in which suprapubic tube or urethral stent was used. In 56 of the 105 patients in whom suprapubic diversion was used, four (7.14%) had fistulas and three (5.35%) had meatal stenosis, in contrast to a fistula rate of 14.28% and meatal stenosis rate of 12.24% in patients that urethral stent is used for urinary drainage. CONCLUSION: The authors believe that the use of suprapubic diversion is advantageous for the outcome of one-stage hypospadias repair in relation to fistula occurrence and meatal stenosis.     

Excitons and rare-earth ions in CsCdBr3

CsCdBr₃ has a quasi-linear crystal structure. It consists of covalently bound [CdBr]₆⁴⁻ chains separated by chains of Cs⁺ ions. The trivalent rare-earth (RE) ions substitute for divalent Cd ions forming predominantly pair centers of the type RE³⁺-(Cd vacancy)-RE³⁺. A minority of RE ions forms “single-ion” centers with more distant charge compensation. The electronic structure around the band gap is determined by the [CdBr]₆⁴⁻ octahedra. The lowest excitonic states of the lattice are charge-transfer states of these octahedra. At low temperatures they form self-trapped excitons which become mobile around 80 K.

In addition we find defect-localized excitons at the RE pairs and single ions with slightly modified spectra. There is a strong energy transfer between the RE ions and the defect-localized excitons in both directions with transition times below 10⁻⁸ s. For the cooperative fluorescence transition ¹D₂×¹G₄→³H₄׳H₄ in Pr³⁺: CsCdBr₃ a frequency-modulated vibronic sideband spectrum was found with up to four repetitions of the frequency of the localized optical phonon mode at the ion pair.     

When goal orientations collide: Effects of learning and performance orientation on team adaptability in response to workload imbalance.

The authors draw on resource allocation theory (Kanfer & Ackerman, 1989) to develop hypotheses regarding the conditions under which collective learning and performance orientation have interactive effects and the nature of those effects on teams' ability to adapt to a sudden and dramatic change in workload. Consistent with the theory, results of a laboratory study in which teams worked on a computerized, decision-making task over 3 performance trials revealed that learning and performance orientation had independent effects on team adaptability when teams had slack resources available for managing their changed task. Time helped explain the independent effects of performance orientation. Results also revealed that learning and performance orientation had interactive effects when teams did not have slack resources. Finally, the results of this study indicate that teams lacking slack resources were better able to balance high levels of learning and performance orientation over time with practice on the changed task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)