9,526 research outputs found

    Mask Programmable CMOS Transistor Arrays for Wideband RF Integrated Circuits

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    A mask programmable technology to implement RF and microwave integrated circuits using an array of standard 90-nm CMOS transistors is presented. Using this technology, three wideband amplifiers with more than 15-dB forward transmission gain operating in different frequency bands inside a 4-22-GHz range are implemented. The amplifiers achieve high gain-bandwidth products (79-96 GHz) despite their standard multistage designs. These amplifiers are based on an identical transistor array interconnected with application specific coplanar waveguide (CPW) transmission lines and on-chip capacitors and resistors. CPW lines are implemented using a one-metal-layer post-processing technology over a thick Parylene-N (15 mum ) dielectric layer that enables very low loss lines (~0.6 dB/mm at 20 GHz) and high-performance CMOS amplifiers. The proposed integration approach has the potential for implementing cost-efficient and high-performance RF and microwave circuits with a short turnaround time

    Warabandi in Pakistan's canal irrigation systems: Widening gap between theory and practice

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    Irrigation scheduling / Irrigation systems / Irrigation canals / Privatization / Water rights / Social aspects / Economic aspects / Watercourses / Water supply / Equity / Water distribution / Water users' associations / Pakistan / Punjab

    Institutional perspectives of land reclamation operations in Punjab: A case study of the Lower Chenab Canal (East) Circle Area

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    Land reclamationSoil salinityIrrigated sitesIrrigation canalsIrrigation waterInstitutionsLegal aspectsIrrigation schedulingWater availabilityIrrigated farmingCase studies

    Association of inferior vena cava filter placement for venous thromboembolic disease and a contraindication to anticoagulation with 30-day mortality

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    Importance: Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group. Objective: To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias. Design, Setting, and Participants: This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018. Exposure: Inferior vena cava filter placement. Main Outcomes and Measures: Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable. Results: Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). Conclusions and Relevance: After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation

    Coherent Topological Charge Structure in CPN1CP^{N-1} Models and QCD

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    In an effort to clarify the significance of the recent observation of long-range topological charge coherence in QCD gauge configurations, we study the local topological charge distributions in two-dimensional CPN1CP^{N-1} sigma models, using the overlap Dirac operator to construct the lattice topological charge. We find long-range sign coherence of topological charge along extended one-dimensional structures in two-dimensional spacetime. We discuss the connection between the long range topological structure found in CPN1CP^{N-1} and the observed sign coherence along three-dimensional sheets in four-dimensional QCD gauge configurations. In both cases, coherent regions of topological charge form along membrane-like surfaces of codimension one. We show that the Monte Carlo results, for both two-dimensional and four-dimensional gauge theory, support a view of topological charge fluctuations suggested by Luscher and Witten. In this framework, the observed membranes are associated with boundaries between ``k-vacua,'' characterized by an effective local value of θ\theta which jumps by ±2π\pm 2\pi across the boundary.Comment: 26 page

    1-(4-Bromo­phen­yl)-3-butano­ylthio­urea

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    In the title compound, C11H13BrN2OS, there are two independent mol­ecules (A and B) in the asymmetric unit. The dihedral angle between the mean planes of the benzene ring and the carbamothioyl group is 63.66 (mol­ecule A) and 80.3 (0)° (mol­ecule B). The butanamide group in mol­ecule A is disordered [0.532 (6) and 0.468 (6) occupancy]. The carbamothioyl group is twisted by 63.6 (6) (mol­ecule A) and 80.3 (0)° (mol­ecule B) from the respective benzene ring. A strong intra­molecular N—H⋯O hydrogen bond occurs in each mol­ecule. The crystal packing is stabilized by weak inter­molecular N—H⋯O and N—H⋯S hydrogen-bond inter­actions, the latter forming an infinite co-operative hydrogen-bonded two-dimensional network along [110]
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