273 research outputs found

    Worst-case MOSFET parameter extraction for a 2μm CMOS process

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    This paper will describe the process by which realistic nominal and worstcase DC MOSFFT model parameter sets were determined and validated for a 2μm CMOS technology. The steps involved in this task, which will be detailed, ranged from the definition of a suitable circuit simulator model. through the collection of statistical parametric data, to the generation and verification of the worstcase model sets obtained from this data

    Wesson's IMT with a Weylian bulk

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    The foundations of Wesson's induced matter theory are analyzed. It is shown that the 5D empty bulk must be regarded rather as a Weylian space than as a Riemannian one.The framework of a Weyl-Dirac version of Wesson's theory is elaborated and discussed. The bulk possesses in addition to the metric tensor a Weylian connection vector as well Dirac's gauge function; there are no sources (mass, current) in the bulk. On the 4D brane one obtains a geometrically based unified theory of gravitation and electromagnetism with mass, currents and equations induced by the 5D bulkComment: 29 page

    Improvement of convective drying of carrot by applying power ultrasound. Influence of mass load density

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    [EN] Power ultrasound is considered to be a novel and promising technology with which to improve heat and mass transfer phenomena in drying processes. The aim of this work was to contribute to the knowledge of ultrasound application to air drying by addressing the influence of mass load density on the ultrasonically assisted air drying of carrot. Drying kinetics of carrot cubes were carried out (in triplicate) with or without power ultrasound application (75 W, 21.7 kHz) at 40 C, 1 m/s, and several mass load densities: 12, 24, 36, 42, 48, 60, 72, 84, 96, 108, and 120 kg/m3 . The experimental results showed a significant (p < 0.05) influence of both factors, mass load density and power ultrasound application, on drying kinetics. As expected, the increase of mass load density did not affect the effective moisture diffusivity (De, m2 /s) but produced a reduction of the mass transfer coefficient (k, kg water/m2 /s). This was explained by considering perturbations in the air flow through the drying chamber thus creating preferential pathways and, as a consequence, increasing external mass transfer resistance. On the other hand, it was found that the power ultrasound application increased the mass transfer coefficient and the effective moisture diffusivity regardless of the mass load density used. However, the influence of power ultrasound was not significant at the highest mass load densities tested (108 and 120 kg/m3 ), which may be explained from the high ratio (acoustic energy/sample mass) found under those experimental conditions. Therefore, the application of ultrasound was considered as a useful technology with which to improve the convective drying, although its effects may be reduced at high mass load densities.The authors acknowledge the financial support of the Spanish Ministry of Science and Technology (DPI2009-14549-C04-04) and the Universidad Politecnica de Valencia (PAID-06-08-3180).Cárcel Carrión, JA.; García Pérez, JV.; Riera, E.; Mulet Pons, A. (2011). Improvement of convective drying of carrot by applying power ultrasound. Influence of mass load density. Drying Technology. 29(2):174-182. https://doi.org/10.1080/07373937.2010.483032S17418229

    Meaning and Dialogue Coherence: A Proof-theoretic Investigation

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    This paper presents a novel proof-theoretic account of dialogue coherence. It focuses on an abstract class of cooperative information-oriented dialogues and describes how their structure can be accounted for in terms of a multi-agent hybrid inference system that combines natural deduction with information transfer and observation. We show how certain dialogue structures arise out of the interplay between the inferential roles of logical connectives (i.e., sentence semantics), a rule for transferring information between agents, and a rule for information flow between agents and their environment. The order of explanation is opposite in direction to that adopted in game-theoretic semantics, where sentence semantics (or a notion of valid inference) is derived from winning dialogue strategies. That approach and the current one may, however, be reconcilable, since we focus on cooperative dialogue, whereas the game-theoretic tradition concentrates on adversarial dialogue

    Rheological behavior of thermoreversible k-carrageenan/nanosilica gels

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    The rheological behavior of silica/κ-carrageenan nanocomposites has been investigated as a function of silica particle size and load. The addition of silica nanoparticles was observed to invariably impair the gelation process, as viewed by the reduction of gel strength and decrease of gelation and melting temperatures. This weakening effect is seen, for the lowest particle size, to become slightly more marked as silica concentration (or load) is increased and at the lowest load as particle size is increased. These results suggest that, under these conditions, the particles act as physical barriers to polysaccharide chain aggregation and, hence, gelation. However, for larger particle sizes and higher loads, gel strength does not weaken with size or concentration but, rather, becomes relatively stronger for intermediate particles sizes, or remains unchanged for the largest particles, as a function of load. This indicates that larger particles in higher number do not seem to increasingly disrupt the gel, as expected, but rather promote the formation of stable gel network of intermediate strength. The possibility of this being caused by the larger negative surface charge found for the larger particles is discussed. This may impede further approximation of neighboring particles thus leaving enough inter-particle space for gel formation, taking advantage of a high local polysaccharide concentration due to the higher total space occupied by large particles at higher loads.FCT - PTDC/QUI/67712/2006FEDE

    Characterization of the peripheral thyroid system of gilthead seabream acclimated to different ambient salinities

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    Thyroid hormones are involved in many developmental and physiological processes, including osmoregulation. The regulation of the thyroid system by environmental salinity in the euryhaline gilthead seabream (Sparus aurata) is still poorly characterized. To this end seabreams were exposed to four different environmental salinities (5, 15, 40 and 55 ppt) for 14 days, and plasma free thyroid hormones (fT3, ff4), outer ring deiodination and Na+/K+ -ATPase activities in gills and kidney, as well as other osmoregulatory and metabolic parameters were measured. Low salinity conditions (5 ppt) elicited a significant increase in fT3 (29%) and ff4 (184%) plasma concentrations compared to control animals (acclimated to 40 ppt, natural salinity conditions in the Bay of Cadiz, Spain), while the amount of pituitary thyroid stimulating hormone subunit 13 (tshb) transcript abundance remained unchanged. In addition, plasma fT4 levels were positively correlated to renal and branchial deiodinase type 2 (dio2) mRNA expression. Gill and kidney T4-outer ring deiodination activities correlated positively with dio2 mRNA expression and the highest values were observed in fish acclimated to low salinities (5 and 15 ppt). The high salinity (55 ppt) exposure caused a significant increase in tshb expression (65%), but deiodinase gene expression (diol and dio2) and activity did not change and were similar to controls (40 ppt). In conclusion, acclimation to different salinities led to changes in the peripheral regulation of thyroid hormone metabolism in seabream. Therefore, thyroid hormones are involved in the regulation of ion transport and osmoregulatory physiology in this species. The conclusions derived from this study may also allow aquaculturists to modulate thyroid metabolism in seabream by adjusting culture salinity. (C) 2016 Elsevier Inc. All rights reserved.Socrates/Erasmus Grant from the European UnionUniversity of Cadiz [UCA 2009-074-FPI]Ministerio de Education y Ciencia, Spain [AGL2007-61211/ACU]FEDER, Spain [AGL2007-61211/ACU]Proyecto de Excelencia (Junta de Andalucia) [PO7-RNM-02843]Science Foundation (FCT) of Portugal [SFRH/BPD/89889/2012, SFRH/BPD/84033/2012]info:eu-repo/semantics/acceptedVersio

    Fertility, Living Arrangements, Care and Mobility

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    There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century – demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed

    Impacto da adubação orgânica sobre a incidência de tripes em cebola.

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    Analisou-se a relação entre adubação orgânica e a incidência de Thrips tabaci Lind. em cebola (Allium cepa L), na EE de Ituporanga,entre agosto e dezembro de 1998. Os tratamentos foram determinados de acordo com a necessidade de N para a cultura pela análise de solo. Empregou-se como fonte orgânica diversos adubos fornecendo 75 Kg/ha de N (esterco suíno; adubo Barriga Verde proveniente de esterco de aves; composto orgânico; esterco de peru; húmus); 37,5 Kg/ha de N (metade da dose normal com esterco de suíno); as testemunhas foram adubação mineral fornecendo 30-120-60 kg/ha de N-P2O5-K2O e o dobro da dose (60-240-120 kg/ha de N-P2O5-K2O); e testemunha sem adubação. Nenhum tratamento apresentou incidência de T. tabaci superior à testemunha sem adubo. A adubação mineral em relação à orgânica não favoreceu significativamente a incidência de T. tabaci . O processo de conversão do manejo do solo da área experimental de convencional para orgânico pode ter favorecido a infestação similar do inseto entre tratamentos. No período de maior incidência de T. tabaci, a relação com nutrientes foi descrita por um modelo envolvendo K/Zn, B e N de maneira positiva. A correlação entre nutrientes e T. tabaci não foi linear na maioria das avaliações. A adubação orgânica pode substituir a adubação mineral na cultura da cebola, pois foi possível atingir níveis de produtividade similares para ambos tratamentos

    Central arterial stiffness is associated with structural brain damage and poorer cognitive performance: The ARIC study

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    Background Central arterial stiffening and increased pulsatility, with consequent cerebral hypoperfusion, may result in structural brain damage and cognitive impairment. Methods and Results We analyzed a cross‐sectional sample of ARIC‐NCS(Atherosclerosis Risk in Communities–Neurocognitive Study) participants (aged 67–90 years, 60% women) with measures of cognition (n=3703) and brain magnetic resonance imaging (n=1255). Central arterial hemodynamics were assessed as carotid‐femoral pulse wave velocity and pressure pulsatility (central pulse pressure). We derived factor scores for cognitive domains. Brain magnetic resonance imaging using 3‐Tesla scanners quantified lacunar infarcts; cerebral microbleeds; and volumes of white matter hyperintensities, total brain, and the Alzheimer disease signature region. We used logistic regression, adjusted for demographics, apolipoprotein E ɛ4, heart rate, mean arterial pressure, and select cardiovascular risk factors, to estimate the odds of lacunar infarcts or cerebral microbleeds. Linear regression, additionally adjusted for intracranial volume, estimated the difference in log‐transformed volumes of white matter hyperintensities, total brain, and the Alzheimer diseasesignature region. We estimated the mean difference in cognitive factor scores across quartiles of carotid‐femoral pulse wave velocity or central pulse pressure using linear regression. Compared with participants in the lowest carotid‐femoral pulse wave velocity quartile, participants in the highest quartile of carotid‐femoral pulse wave velocity had a greater burden of white matter hyperintensities (P=0.007 for trend), smaller total brain volumes (−18.30 cm 3 ; 95% CI, −27.54 to −9.07 cm 3 ), and smaller Alzheimer disease signature region volumes (−1.48 cm 3 ; 95% CI, −2.27 to −0.68 cm 3 ). These participants also had lower scores in executive function/processing speed (β=−0.04 z score; 95% CI, −0.07 to −0.01 z score) and general cognition (β=−0.09 z score; 95% CI, −0.15 to −0.03 z score). Similar results were observed for central pulse pressure. Conclusions Central arterial hemodynamics were associated with structural brain damage and poorer cognitive performance among older adults
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