11,454 research outputs found
Modelling delay and noise in arbitrarily coupled RC trees.
No full textClosed-form equations for second-order transfer functions of general arbitrarily coupled resistance-capacitance (RC) trees with multiple drivers are reported. The models allow precise delay and noise calculations for systems of coupled interconnects with guaranteed stability and represent the minimum complexity associated with this class of circuits. Their accuracy is extensively compared against other relevant models and is found to be better or comparable to more expensive models. All results are derived from a theoretical approach, and their physical basis is examined. The simplicity, accuracy, and generality of the models make them suitable for use in early signal integrity analyses of complex systems and incremental physical optimization
Closed form metrics to accurately model the response in general arbitrarily-coupled RC trees.
No full textClosed form expressions are presented for the first and second moment of the impulse response for arbitrarily-coupled RC trees with multiple drivers, and used to generate accurate second order estimations of the transfer function from any driver to the receiver. The superposition of the waveforms for all switching events allows precise delay and noise calculations for systems of coupled interconnects with different aggressor arrival times, with a minimum of computational complexity
Experimental response of RC columns built with plain bars under unidirectional cyclic loading
No full textA large number of existing reinforced concrete (RC) buildings structures were designed and built before mid-70’s, when the reinforcing bars had plain surface and prior to the enforcement of the modern seismic-oriented design philosophies.
This paper describes a series of unidirectional cyclic tests performed on seven full-scale columns built with plain reinforcing bars, without adequate reinforcement detailing for seismic demands. The specimens have different reinforcing steel details and different cross sections. A further monotonic test was also carried out for one of the specimens and an additional column, built with deformed bars, was cyclically tested for comparison with the results for the specimens with plain bars. The main experimental results are presented and discussed. The influence of bond properties on the column behaviour is evidenced by differences observed between the cyclic response of similar specimens with plain and deformed bars. The influence of reinforcement amount and displacement history on the column response is also investigated
International Committee of Red Cross and RC Movement - Council of Delegates
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/362493Red Cross File Classification Code: 10R99436
item: [2015.0033.08426] "International Committee of Red Cross and RC Movement - Council of Delegates
Analytic modeling of interconnects for deep submicron circuits.
No full textClosed form equations for second order transfer functions of general arbitrarily-coupled RC trees with multiple drivers are reported. The models allow precise delay and noise calculations for systems of coupled interconnects with guaranteed stability, and represent the minimum complexity associated with this class of circuits. The simplicity, accuracy and generality of the models make them suitable for use in early delay and noise planning of global signals in complex systems
Ultimate Bearing Capacity of RC Cross-sections in Biaxial Bending
No full textIn the graduation thesis is presented the analysis of ultimate bearing capacity and a computer program in the programming language Matlab for designing double eccentrically loaded reinforced concrete cross-sections. The principles of the analysis are according to EC 2 (Design of concrete structures – Part 1: General rules and rules for buildings, prEN 1992-1-1 (Revised final draft):2002) and the basis of the presented method of design are design interaction charts. The particularity of these design charts is that for each case of RC rectangular cross-section there are ten interaction diagrams produced for ten different ratios of standardized bending moments mzd/myd. The vertical axis of the interaction diagram presents standardized axial load nd and the horizontal axis presents standardized bending moment myd (mzd = r⋅myd). A great precision of the presented method for designing biaxially bent RC cross-sections is proved at typical rectangualar RC cross-sections
Redefinition of hypereosinophilic disorders based on an analysis of 28 cases of FIP1L1-PDGFRA negative persistent unexplained eosinophilia (PUE) with eosinophil end-organ damage (EEOD)
No full textIn 1997 the term eosinophil end-organ damage(EEOD) was introduced to facilitate management of patients with high eosinophil counts in whom damage to organs such as heart, lungs, and skin by eosinophils was associated with persistent unexplained eosinophilia (no obvious cause for eosinophilia was identified). In 2003 Cools et al identified the presence of the FIP1L1-PDGFRA gene as the causation of eosinophilia in 50% of cases of hypereosinophilic syndromes with end organ damage. Cases which are negative for this gene and a Tcell clone appear to form a distinctive group whose aetiopathogenesis and clinical significance are different. In order to identify the extent of end organ damage in FIP1L1-PDGFRA negative cases and/or identify rarer causes of unexplained eosinophilia in all cases of eosinophilia presenting from 14.06.2002 to 14.06.2006, we looked at all patients who had persistent eosinophilia present on two separate blood tests done I month apart with eosinophil counts greater than 1–1.5 x 10 9/l. All cases of unexplained eosinophilia (Eosinophil count greater than 1– 1.5 x 10 9/L) seen at our institution in a 4 year period in whom no obvious cause of eosinophilia was found were evaluated for the presence of the FIP1L1-PDGFRA gene, TEL-PDGFRB and variant BCR-ABL gene. Of 40 cases seen 2 men were FIP1L1-PDGFRA positive, 3 others (2 men and 1 woman) had myeloproliferative diseases, I man had clozapine induced eosinophilia, one woman Kimura Weils disease and 1 man had cutaneous mastocytosis . There were 28 cases (14 women, 2 children,12 men) who were FIP1L1 -PDGFRA negative and had persistent unexplained eosinophilia without clonal T cells. These cases were followed up over a 4 year period and tested serially for damage to end organs by eosinophils. FIP1L1-PDGFRA was tested and found negative on two separate occasions. Ig E levels had to be less then 500 iu/l to exclude allergy and a therapeutic trial of mebendazole 100mg daily for three days was given in all cases even if parasite testing did not identify a parasitic infestation. There were 28 cases (14 women, 2 children,12 men) who were FIP1L1-PDGFRA negative which contrasts with the Male Female ratio seen in FIP1 L1-PDGFRA positive cases in which males predominate. The age ranged from 9–80. Four year follow up identified a chronic illness in these cases with no damage to vital organs. Clinical symptoms complained of included fatigue(28), joint and muscle pains(28), skin rashes(10), blackouts(1), thrombotic events(2), diarrhoea(2), fasciitis(2), gastroenteritis(2), cough(2), and breathlessness(2). No organomegaly was seen. In one clonal T cells were identified on serial testing after 1 year of follow up. We conclude that cases of FIP1L1-PDGFRA negative hypereosinophilia are a distinct group with a chronic illness mainly affecting skin and joints who respond well to symptomatic treatment, oral steroids, or hydroxyurea. We believe that hypereosinophilic diorders need to be redined as PUEand EEOD. When both PUE and EEOD are present the diagnosis is HES
A Compact 10-MHz RC Frequency Reference With a Versatile Temperature Compensation Scheme
No full textThis article presents the design and implementation of a compact CMOS RC frequency reference. It consists of a frequency-locked loop (FLL) that locks the period of a voltage-controlled oscillator (VCO) to the time an RC network takes to charge to a reference voltage. Conventionally, an RC time constant with a near-zero temperature coefficient (TC) is realized by using a trimmed network of resistors with different TCs. In this work, such a network is used to realize a temperature-dependent reference voltage whose TC cancels that of a single-resistor RC time constant. Compared with the conventional approach, which requires resistors with TCs of opposite polarity, the proposed approach can be implemented with resistors with TCs of similar polarity, and so it can be implemented in most CMOS processes. To compensate for RC spread, a trimmed capacitor is used to adjust the nominal frequency. Two prototype chips were made, one based on p- /n-polysilicon resistors and other based on silicided/p-diffusion resistors. Fabricated in a standard 180-nm CMOS technology, the polysilicon-based prototype has an active area of 0.01 mm2 and an absolute inaccuracy of ±2800 ppm from -45 °C to 125 °C with a fixed TC-trim and a one-point frequency trim. After one week of accelerated aging at 150 °C, however, significant drift (5000 ppm) was observed. The diffusion-based prototype exhibits greater inaccuracy (±14 400 ppm) but much less drift (600 ppm).Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A CMOS Dual-RC frequency reference with ±250ppm inaccuracy from -45°C to 85°C
No full textTo comply with wired communication standards such as USB, SATA and PCI/PCI-E, systems-on-chip require frequency references with better than 300ppm accuracy. LC-based references achieve 100ppm accuracy [1], but suffer from high power consumption (∼20mW). Thermal diffusivity (TD) references require less power (∼2mW), at the expense of less accuracy (1000ppm) [2]. RC-based references offer the lowest power consumption, but their accuracy is typically limited to ∼0.1% [3]. In RC relaxation oscillators, comparator offset and delay are the major sources of inaccuracy [4,5]. References based on frequency-locked loops (FLLs) circumvent these by locking an oscillator's frequency to the time-constant of an RC filter, but their accuracy is then limited by the nonlinear temperature dependency of on-chip resistors [3,6].Session 3.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentation(OLD)Applied Quantum ArchitecturesMicroelectronic
Effect of Coexisting Covalent Cross-Links on the Properties of Rotaxane-Cross-Linked Polymers
No full textA protocol or guiding principle for the toughening of
cross-linked
polymers by rotaxane cross-linking is proposed. Rotaxane-cross-linked
polymers (RCPs), which use rotaxane structures at the cross-linking
points, have attracted great interest due to their unique properties
as, e.g., extremely tough elastomers. To investigate the influence
of coexisting covalent cross-linking points on the properties of RCPs,
several hybrid cross-linked polymers (HCPs) with different ratios
between rotaxane- and covalent cross-links were synthesized using
the radical polymerization of n-butyl acrylate in
the presence of a mixture of rotaxane- (RC) and covalent cross-linkers
(CC). The difference in thermal and swelling properties among the
HCPs, RCPs, and covalently cross-linked polymers (CCPs) was small,
whereas the coexistence of a small amount of CCs in the HCPs severely
reduced the fracture energy of the resulting polymers relative to
that of the RCP, thus suggesting a suitable protocol for the molecular
design of tough cross-linked polymers
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