Dielectric response of polymer relaxors

Dielectric response of vinylidene fluoride type ferroelectric polymers is dominated by that of segmental motions in the amorphous phase in temperature range 200–300 K and contributions related to the local mode and ferroelectric–paraelectric transition in the crystalline phase of the polymer at higher temperatures. Diffuse and frequency-dependent dielectric anomaly observed in fast electron irradiated polyvinylidene fluoride-trifluoroethylene P(VDF/TrFE) has been related to relaxor-like behavior induced in the semicrystalline ferroelectric copolymers. As random field and the response of polar nanosize clusters determine the relaxor behavior the effects of disorder and fast electron irradiation (below and above T _C) on the three contributions to the dielectric response of PVDF, P(VDF/TrFE)(75/25) and P(VDF/TrFE)(50/50) are shown. The processes involved in radiation-induced functionalization of PVDF-type polymers are discussed on the basis of results of ESR, IR and Raman spectroscopy studies.     

Design and Realization of a Built-In Current Sensor for IDDQ Testing and Power Dissipation Measurement

Built-in current sensor (BICS) is known to enhance test accuracy, defect coverage of quiescent current (I_DDQ) testing method in CMOS VLSI circuits. For new deep-submicron technologies, BICSs become essential for accurate and practical I_DDQ testing. This paper presents a new BICS suitable for power dissipation measurement and I_DDQ testing. Although the BICS presented in this paper is dedicated to submicron technologies that require reduced supply voltage, it can also be used for applications and technologies requiring normal supply voltage. The proposed BICS has been extended for on-line measurement of the power dissipation using only an additional capacitor. Power dissipation measurement is important for safety-critical applications and battery-powered systems. A simple self-test approach to verify the functionality and accuracy of BICSs has also been introduced. The proposed BICS has been implemented and tested using an N-well CMOS 1.2 m technology. Practical results demonstrate that a very good measurement accuracy can be achieved.     

Chemical characterization of urinary volatile compounds ofPeromyscus californicus,a monogamous biparental rodent

The urinary profiles of adult female and male California mice were examined to determine the volatile compounds that may affect reproduction. The urinary volatiles identified by gas chromatography-mass spectrometry (GC-MS) include ketones, pyrazines, alkanes, nitrile, and aldehyde. None of volatile compounds was specific to males or females. The concentration of urinary volatiles in pregnant and lactating females was significantly higher than in virgin females. Male urinary volatile concentrations were similar to those of pregnant and lactating females. The GC profiles of both sexes were distinguished by a high percentage (36%) of pyrazine derivatives that were also in unusually high concentrations. These compounds may play a wide-ranging role in the control of reproduction in the California mouse.     

Electron paramagnetic resonance evidence for direct co-ordination of copper(II) ions by acrylic resins containing amine groups

Summary E. p. r. and absorption spectra were used to indicate the formation of the complexes between copper (II) ions and acrylic resins containing oligoamines bound via amide bonds to acrylate units. The number of bound nitrogen atoms depends on the length of the amine chain attached to acrylamide unit.     

Multiple fault analog circuit testing by sensitivity analysis

Analog circuit testing is considered to be a very difficult task. This difficulty is mainly due to the lack of fault models and accessibility to internal nodes. To overcome this problem, an approach is presented for analog circuit modeling and testing. The circuit modeling is based on first-order sensitivity computation. The testability of the circuit is analyzed by the multiple-fault model and by functional testing. Component deviations are deduced by measuring a number of output parameters, and through sensitivity analysis and tolerance computation. Using this approach, adequate tests are identified for testing catastrophic and soft faults. Some experimental results are presented for simple models as well as multiple-fault models.     

The effect of dielectric heterogeneity on the pyroelectric responseof PVDF

Understanding the dynamical response to the applied electric and heat field is crucial in pyroelectric applications of polymers, although their heterogeneity on molecular and crystalline level and the nonuniform distribution of electric charge make it complex. We studied the effect of dielectric heterogeneity induced during electric polarization in uniaxially and biaxially oriented PVDF films. Both pyroelectric and dielectric response of PVDF poled in low dc field and corona-charged was measured over a wide frequency range. We find that heterogeneity on the crystalline level is responsible for the piling up of the field-induced electric charges which causes an increase in the relaxation time ascribed to the relaxation process in the MHz range. It is also concluded that the dielectric heterogeneity in is important only in the case when the front electrode of the pyroelectric sensor is that which was grounded during dc poling     

Multimedia polysensory integration training system dedicated to children with educational difficulties

Ranking of search results and ads has traditionally been studied separately. The probability ranking principle is commonly used to rank the search results while the ranking based on expected profits is commonly used for paid placement of ads. These rankings try to maximize the expected utilities based on the user click models. Recent empirical analysis on search engine logs suggests unified click models for both ranked ads and search results (documents). These new models consider parameters of (i) probability of the user abandoning browsing results (ii) perceived relevance of result snippets. However, current document and ad ranking methods do not consider these parameters. In this paper we propose a generalized ranking function—namely Click Efficiency (CE)—for documents and ads based on empirically proven user click models. The ranking considers parameters (i) and (ii) above, optimal and has the same time complexity as sorting. Furthermore, the CE ranking exploits the commonality of click models, hence is applicable for both documents and ads. We examine the reduced forms of CE ranking based upon different underlying assumptions, enumerating a hierarchy of ranking functions. Interestingly, some of the rankings in the hierarchy are currently used ad and document ranking functions; while others suggest new rankings. Thus, this hierarchy illustrates the relationships between different rankings, and clarifies the underlying assumptions. While optimality of ranking is sufficient for document ranking, applying CE ranking to ad auctions requires an appropriate pricing mechanism. We incorporate a second price based mechanism with the proposed ranking. Our analysis proves several desirable properties including revenue dominance over Vickrey Clarke Groves (VCG) for the same bid vector and existence of a Nash equilibrium in pure strategies. The equilibrium is socially optimal, and revenue equivalent to the truthful VCG equilibrium. As a result of its generality, the auction mechanism and the equilibrium reduces to the current mechanisms including Generalized Second Price Auction (GSP) and corresponding equilibria. Furthermore, we relax the independence assumption in CE ranking and analyze the diversity ranking problem. We show that optimal diversity ranking is NP-Hard in general, and a constant time approximation algorithm is not likely. Finally our simulations to quantify the amount of increase in different utility functions conform to the results, and suggest potentially significant increase in utilities.     

Automatic music genre classification based on musical instrument track separation

The aim of this article is to investigate whether separating music tracks at the pre-processing phase and extending feature vector by parameters related to the specific musical instruments that are characteristic for the given musical genre allow for efficient automatic musical genre classification in case of database containing thousands of music excerpts and a dozen of genres. Results of extensive experiments show that the approach proposed for music genre classification is promising. Overall, conglomerating parameters derived from both an original audio and a mixture of separated tracks improve classification effectiveness measures, demonstrating that the proposed feature vector and the Support Vector Machine (SVM) with Co-training mechanism are applicable to a large dataset.     

Effect of chlorine compounds on the deactivation of platinum catalysts

A commercial platinum (Pt) catalyst with 0.15% platinum ingredient (referred to as Pt-O) was investigated for activity in the combustion of chlororganic compounds, for resistance to poisoning, and for potential application to control gas emissions. Investigations were also carried out on six other catalysts. These were platinum catalysts with platinum contents varying from 0.05% to 0.15% and platinum catalysts with palladium or manganese as active ingredients. The catalysts were tested in the oxidation of a chlorobenzene-xylene mixture to determine their poisoning resistance. The presence of manganese was found to have a disadvantageous influence on the combustion of chlororganics.     

Improving the quality of life of caregivers of persons with spinal cord injury: A randomized controlled trial.

Objective: To assess the efficacy of two psychosocial interventions for caregivers of older persons with spinal cord injury (SCI). Design: A multisite, three-group, randomized controlled trial comparing two active intervention conditions with each other and to an information-only control group. One hundred seventy-three caregiver and care-recipient dyads were randomly assigned to one of three conditions: a caregiver-only treatment condition in which caregivers received a multicomponent intervention based on their risk profile; a dual-target condition in which the caregiver intervention was complemented by a treatment targeting the care recipient, designed to address both caregiver and care recipient risk factors; and an information-only control condition in which the caregiver received standard printed information about caregiving, SCI, and aging. Outcome Measures: A multivariate outcome comprised of six indicators linked to the goals of the interventions was the primary outcome of the study. The multivariate outcome included measures of depressive symptoms, burden, social support and integration, self-care problems, and physical health symptoms. Results: At 12 months, caregivers in the dual-target condition had improved quality of life as measured by our multivariate outcome when compared to the control condition. Using the dyad as the unit of analysis, the dual-target condition was superior to both the control condition and the caregiver-only condition in our multivariate outcomes analysis. Dyads enrolled in the dual-target condition had significantly fewer health symptoms than control condition and caregiver-only condition participants and were less depressed when compared to participants in the caregiver-only condition. In follow-up analyses we found that a higher proportion of caregivers in the dual-target condition had clinically significant improvements in depression, burden, and health symptoms when compared with the caregiver-only condition. Conclusion: Caregivers are in need of and can benefit from interventions that help them manage the medical and functional limitations of the care recipient. Intervention strategies that target both the caregiver and care recipient are particularly promising strategies for improving the quality of life of caregivers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)