SLITS LOADED EQUILATERAL TRIANGULAR MICROSTRIP ANTENNA FOR TRIPLE BAND OPERATION

ABSTRACT This paper presents the design and development of a slits loaded equilateral triangular microstrip antenna for triple band operation. The antenna has a volume of 8 X 5 X 0.16 cm 3 and operates between the frequency range of 5.37 to 9.26 GHz giving a maximum impedance bandwidth of 3.83% with a peak gain of 3.14 dB. The simple glass epoxy substrate material is used to fabricate the antenna. The microstripline feed arrangement is incorporated to excite the antenna. The antenna shows linearly polarized broadside radiation characteristic. The design detail of the antenna is described. The experimental results are presented and discussed. This antenna may find applications in IEEE 802.11a and for systems operating in C-band frequencies

COMPLEMENTARY SYMMETRY E-SLOT RECTANGULAR MICROSTRIP ANTENNA FOR TRIPLE OPERATION

ABSTRACT This paper focuses on the design and development of a complementary symmetry E -slot rectangular microstrip antenna for triple band operation. The antenna has a structure of 8 X 5 X 0.16 cm 3 and operates between the frequency range of 5.39 to 8.87 GHz giving a maximum impedance bandwidth of 17.5% with a peak gain of 2.84 dB. The simple low cost glass epoxy substrate material is used to fabricate the antenna. The microstripline feed arrangement is used to excite the antenna. The experimental and simulated results agree each other. The antenna shows linearly polarized broadside radiation characteristic. The design detail of the antenna is described. The experimental results are presented and discussed. This antenna may find applications for systems operating in IEEE 802.11a and C-band of frequencies

The United States COVID-19 Forecast Hub dataset

Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks

Randomized Clinical Trial of High-Dose Rifampicin With or Without Levofloxacin Versus Standard of Care for Pediatric Tuberculous Meningitis: The TBM-KIDS Trial

Background. Pediatric tuberculous meningitis (TBM) commonly causes death or disability. In adults, high-dose rifampicin may reduce mortality. The role of fluoroquinolones remains unclear. There have been no antimicrobial treatment trials for pediatric TBM. Methods. TBM-KIDS was a phase 2 open-label randomized trial among children with TBM in India and Malawi. Participants received isoniazid and pyrazinamide plus: (i) high-dose rifampicin (30 mg/kg) and ethambutol (R30HZE, arm 1); (ii) high-dose rifampicin and levofloxacin (R30HZL, arm 2); or (iii) standard-dose rifampicin and ethambutol (R15HZE, arm 3) for 8 weeks, followed by 10 months of standard treatment. Functional and neurocognitive outcomes were measured longitudinally using Modified Rankin Scale (MRS) and Mullen Scales of Early Learning (MSEL). Results. Of 2487 children prescreened, 79 were screened and 37 enrolled. Median age was 72 months; 49%, 43%, and 8% had stage I, II, and III disease, respectively. Grade 3 or higher adverse events occurred in 58%, 55%, and 36% of children in arms 1, 2, and 3, with 1 death (arm 1) and 6 early treatment discontinuations (4 in arm 1, 1 each in arms 2 and 3). By week 8, all children recovered to MRS score of 0 or 1. Average MSEL scores were significantly better in arm 1 than arm 3 in fine motor, receptive language, and expressive language domains (P < .01). Conclusions. In a pediatric TBM trial, functional outcomes were excellent overall. The trend toward higher frequency of adverse events but better neurocognitive outcomes in children receiving high-dose rifampicin requires confirmation in a larger trial. Clinical Trials Registration. NCT02958709

Impurity Diffusion Coefficients Of Al And Zn In Mg Determined From Solid-To-Solid Diffusion Couples

Increasing use and development of lightweight Mg-alloys have led to the desire for more fundamental research in and understanding of Mg-based systems. As property enhancing components, Al and Zn are two of the most important and common alloying elements for Mg-alloys. We have investigated the concentration dependent interdiffusion of Al and Zn in Mg using diffusion couples of pure polycrystalline Mg mated to Mg solid solutions containing either \u3c9 at.% Al or \u3c3 at.% Zn. Concentration profiles were determined by electron micro-probe microanalysis of the diffusion zone. The interdiffusion coefficients were determined by the classical Boltzmann-Matano method within the Mg solid solution. As the concentration of Al or Zn approaches the dilute ends, we employ an analytical approach based on the Hall method to estimate the impurity diffusion coefficients. Results of Al and Zn impurity diffusion in Mg are reported and compared to published impurity diffusion coefficients typically determined by thin film techniques

Aluminum Impurity Diffusion In Magnesium

This is the second part of a 3-part examination of what may be potentially expected from the 2010 national health care reform legislation. Political researchers and pundits have speculated endlessly on the many changes mandated by the 2010 national health care reform legislation, styled the Patient Protection and Affordable Care Act. A review and assessment of this legislation at several levels (federal, state, state agency, local region, and individual business leaders) were undertaken. The results of this expanded analysis suggest strongly that, nationally, members of the business community and their employees will benefit from the legislation early on (years 1 through 3) and then likely will be impacted adversely as the payment mechanisms driving the legislation are tightened by new federal regulations (year 4 onward). As a result of this research, it is surmised that businesses will be immediately impacted by the legislation, with small business owners being the prime beneficiaries of the new legislation, owing to the availability of coverage to approximately 32 million individuals who previously had no access to coverage. In that regard, the soon-to-be-newly insured population also will be a prime beneficiary of the legislation as the limitations on chronic illnesses and other preexisting conditions will be reduced or eliminated by the legislation. Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Impurity And Tracer Diffusion Studies In Magnesium And Its Alloys

An Integrated Computational Materials Engineering (ICME) approach for optimizing processing routes for Mg-alloys requires reliable thermodynamic and diffusion databases. We are developing an impurity and tracer diffusion database using both stable and unstable isotopes for Mg and its alloys. In this study, Al impurity diffusion in pure polycrystalline Mg (99.9%) was examined using the thin film method. Approximately 500 nm thick Al films were deposited on in-situ RF plasma-cleaned polycrystalline Mg by DC magnetron sputtering from pure Al (99.9%) targets. Specimens were then diffusion annealed at 300 and 400°C in quartz capsules that were evacuated to 10-8 torr and backfilled with Ar-H2 mixtures. Concentration profile of Al diffusion profiles into single phase Mg was determined by depth-profiling technique using secondary ion mass spectroscopy. The Al impurity diffusion coefficients were determined at 300 and 400°C as 1.74 (±0.4) x 10-17 m2/sec and 2.38 (±1.0) x 10-15 m2/sec, respectively