A5064902135- Air Quality and Health Impacts
- Energy and Environment Impacts
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Noise Effects and Management
- Black Holes and Theoretical Physics
- Indoor Air Quality and Microbial Exposure
- Cosmology and Gravitation Theories
- Energy, Environment, and Transportation Policies
- Climate Change and Health Impacts
- Wind and Air Flow Studies
- Occupational and environmental lung diseases
- Aerosol Filtration and Electrostatic Precipitation
- Plant Surface Properties and Treatments
- Gamma-ray bursts and supernovae
- Smoking Behavior and Cessation
- Hybrid Renewable Energy Systems
- COVID-19 impact on air quality
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Infection Control and Ventilation
- Carbon Dioxide Capture Technologies
- Cyclone Separators and Fluid Dynamics
RTI International
2016-2025
Research Triangle Park Foundation
2009-2015
Environmental Protection Agency
2010-2012
Max Planck Institute for Gravitational Physics
2002-2009
Max Planck Society
2006-2009
University of Southampton
2005-2008
University of Vienna
2000-2002
University of North Carolina at Chapel Hill
1999-2000
University of British Columbia
1985-1999
Island Health
1984-1985
Gravitational waveforms from the inspiral and ring-down stages of binary black-hole coalescences can be modeled accurately by approximation/perturbation techniques in general relativity. Recent progress numerical relativity has enabled us to model also nonperturbative merger phase coalescence problem. This enables coherently search for all three nonspinning black holes using a single template bank. Taking our motivation these results, we propose family which inspiral, merger, that follow...
The final evolution of a binary-black-hole system gives rise to recoil velocity if an asymmetry is present in the emitted gravitational radiation. Measurements this effect for nonspinning binaries with unequal masses have pointed out that kick velocities $\ensuremath{\sim}175\text{ }\text{ }\mathrm{km}/\mathrm{s}$ can be reached mass ratio $\ensuremath{\simeq}0.36$. However, larger obtained equal-mass provided by spins. Using two independent methods we show merger such yields as large...
Background Higher ambient fine particulate matter (PM 2.5 ) levels can be associated with increased blood pressure and vascular dysfunction. Objectives To determine the differential effects on function of daily changes in community ambient- versus personal-level PM measurements. Methods Cardiovascular outcomes included tone measured 65 non-smoking subjects. exposure metrics 24 h integrated personal- (by vest monitors) community-based for up to 5 consecutive days (357 observations)....
We present a new technique for the numerical simulation of axisymmetric systems. This avoids coordinate singularities which often arise when cylindrical or polar-spherical finite difference grids are used, particularly in simulating tensor partial differential equations like those 3+1 relativity. For system about z axis, basic idea is to use three-dimensional Cartesian(x,y,z) grid covers (say) y=0 plane, but only one finite-difference-molecule–width thick y direction. The field variables...
We review various algorithms for finding apparent horizons in 3 + 1 numerical relativity. then focus on one particular algorithm, which we pose the horizon equation $H\ensuremath{\equiv}{\ensuremath{\nabla}}_{i}{n}^{i}+{K}_{\mathrm{ij}}{n}^{i}{n}^{j}\ensuremath{-}K=0$ as a nonlinear elliptic (boundary-value) PDE angular-coordinate space shape function $r=h(\ensuremath{\theta}, \ensuremath{\varphi})$, finite difference this PDE, and use Newton's method or variant to solve equations. describe...
This work investigated the resuspension and subsequent translocation of particulate matter (PM) from carpeted flooring surfaces due to walking. In addition, effect HVAC systems ceiling fans on mixing and/or resuspended PM was studied. Testing took place both in a residence with well-worn, soiled carpet an environmental test chamber. Prescribed walking occurred measurements taken at multiple sampling heights. Scanning electron microscopy (SEM) fibers used determine fraction dust available for...
Solid fuel burning cookstoves are a major source of household air pollution (HAP) and significant environmental health risk in Sri Lanka. We report results the first field study Lanka to include direct measurements both real-time indoor concentrations personal exposures fine particulate matter (PM2.5) households using two most common stove types A purposive sample 53 was selected rural community Kopiwatta central Lanka, roughly balanced for type (traditional or improved 'Anagi') ventilation...
Traditional cooking using biomass is associated with ill health, local environmental degradation, and regional climate change. Clean stoves (liquefied petroleum gas (LPG), biogas, electric) are heralded as a solution, but few studies have demonstrated their health benefits in field settings. We analyzed the impact of mainly biogas (as well electric LPG) stove use on social, environmental, outcomes two districts Odisha, India, where Indian government has promoted household biogas. established...
The PM2.5 standard proposed by the U.S. Environmental Protection Agency (EPA) has stimulated research on relationships between particulate matter concentrations and exposures subsequent health responses of sensitive subpopulations, such as elderly. Since individuals in these subpopulations may spend more than 90% their time indoors, understanding relationship outdoor particle those found indoor microenvironments is critical. This resulted a time-dependent air quality model incorporating all...
We present a detailed analysis of binary black hole evolutions in the last orbit and demonstrate consistent convergent results for trajectories individual bodies. The gauge choice can significantly affect overall accuracy evolution. It is possible to reconcile certain gauge-dependent discrepancies by examining convergence limit. illustrate these using an initial data set recently evolved Brügmann et al. [Phys. Rev. Lett. 92, 211101 (2004)10.1103/PhysRevLett.92.211101]. For our highest...
Agriculturalists in less-developed countries (LDC) have lower progesterone levels than urban industrialized populations. However, it is unknown if LDC populations are also relatively lower. We tested whether Bolivia samples-poorer (Bol-p) and better-off (Bol-b)-have a Chicago (USA) sample, rate of ovulation Bol-p Bol-b.Serial salivary samples collected from Bolivians, screened according to strict exclusion criteria during two complete menstrual cycles, were radioimmunoassayed for...
We describe an explicit in time, finite-difference code designed to simulate black holes by using the excision method. The is based upon harmonic formulation of Einstein equations and incorporates several features regarding well-posedness numerical stability initial-boundary problem for quasilinear wave equation. After a discussion solved techniques employed, we present series testbeds carried out validate code. Such tests range from evolution isolated head-on collision two then binary hole...
Emissions from indoor biomass burning are a major public health concern in developing areas of the world. Less is known about air quality, particularly airborne endotoxin, homes fuel residential wood stoves higher income countries. A filter-based sampler was used to evaluate wintertime coarse particulate matter (PM10-2.5) and endotoxin (EU/m3, EU/mg) concentrations 50 using as their primary source heat western Montana. We investigated number residents, pets, dampness (humidity), frequency...
Few studies have examined particulate matter (PM) exposure from self-reported use of wood stoves and other indoor combustion sources in urban settings developed countries. We measured concentrations PM < 2.5 microns (PM2.5) for one week with the MicroPEM™ nephelometer 36 households greater Oslo, Norway metropolitan area. PM2.5 levels relation to during a 7 day monitoring period using mixed effects linear models adjustment ambient levels. Mean hourly were higher (p = 0.04) 14 homes stove...
Mist generated by machining processes is formed three mechanisms: impaction, centrifugal force, and evaporation/condensation. This study characterized the size distribution of soluble mineral oil mists that resulted from these formation mechanisms. Salient parameters influencing particle distributions also were identified. Variables investigated included metalworking fluid characteristics. The mist on a small lathe each mechanism was measured using an Aerosizer LD. For only viscosity...
We study the fully nonlinear dynamical evolution of binary black hole data, whose orbital parameters are specified via effective potential method for determining quasicircular orbits. The cases studied range from Cook-Baumgarte innermost stable circular orbit (ISCO) to significantly beyond that separation. In all we find holes coalesce (as determined by appearance a common apparent horizon) in less than half an period. results numerical simulations indicate initial not actually orbits, but...
A large-eddy simulation/immersed boundary method for particulate flows in an Eulerian framework is utilized to investigate short-term particle re-suspension due human motion. The simulations involve a walking through room, stopping, and then place, causing particles be re-suspended from carpet. carpet layer modeled as the porous medium classical adhesive force model applied resistance of carpet-bound material hydrodynamic forcing. effects parameters such foot penetration depth coefficient on...