An imaging system for PLIF/Mie measurements for a combusting flow

The equipment required to establish an imaging system can be divided into four parts: (1) the light source and beam shaping optics; (2) camera and recording; (3) image acquisition and processing; and (4) computer and output systems. A pulsed, Nd:YAG-pummped, frequency-doubled dye laser which can freeze motion in the flowfield is used for an illumination source. A set of lenses is used to form the laser beam into a sheet. The induced fluorescence is collected by an UV-enhanced lens and passes through an UV-enhanced microchannel plate intensifier which is optically coupled to a gated solid state CCD camera. The output of the camera is simultaneously displayed on a monitor and recorded on either a laser videodisc set of a Super VHS VCR. This videodisc set is controlled by a minicomputer via a connection to the RS-232C interface terminals. The imaging system is connected to the host computer by a bus repeater and can be multiplexed between four video input sources. Sample images from a planar shear layer experiment are presented to show the processing capability of the imaging system with the host computer

A planar reacting shear layer system for the study of fluid dynamics-combustion interaction

A versatile planar reacting shear layer facility is constructed at NASA-Lewis. The research objectives, as well as design, instrumentations and the operational procedures developed for the system are described. The fundamental governing equations and the type of quantitative information that are needed from experiments are described. Additionally, a review of earlier work is presented. Whenever appropriate, comparisons are made with similar systems in other facilities and the main differences are described. Finally, the nonintrusive measurement techniques (PLIF, PMS, LDV, and Schlieren photography) and the type of experiments that are planned are described

Investigating the response of leaf area index to droughts in southern African vegetation using observations and model-simulations

In many regions of the world, frequent and continual dry spells are exacerbating drought conditions, which have severe impacts on vegetation biomes. Vegetation in southern Africa is among the most affected by drought. Here, we assessed the spatiotemporal characteristics of meteorological drought in southern Africa using the standardized precipitation evapotranspiration index (SPEI) over a 30-year period (1982–2011). The severity and the effects of droughts on vegetation productiveness were examined at different drought timescales (1- to 24-month timescales). In this study, we characterized vegetation using the leaf area index (LAI) after evaluating its relationship with the normalized difference vegetation index (NDVI). Correlating the LAI with the SPEI, we found that the LAI responds strongly (r=0.6) to drought over the central and southeastern parts of the region, with weaker impacts (r<0.4) over parts of Madagascar, Angola, and the western parts of South Africa. Furthermore, the latitudinal distribution of LAI responses to drought indicates a similar temporal pattern but different magnitudes across timescales. The results of the study also showed that the seasonal response across different southern African biomes varies in magnitude and occurs mostly at shorter to intermediate timescales. The semi-desert biome strongly correlates (r=0.95) to drought as characterized by the SPEI at a 6-month timescale in the MAM (March–May; summer) season, while the tropical forest biome shows the weakest response (r=0.35) at a 6-month timescale in the DJF (December–February; hot and rainy) season. In addition, we found that the spatial pattern of change of LAI and SPEI are mostly similar during extremely dry and wet years, with the highest anomaly observed in the dry year of 1991, and we found different temporal variability in global and regional responses across different biomes. We also examined how well an ensemble of state-of-the-art dynamic global vegetation models (DGVMs) simulate the LAI and its response to drought. The spatial and seasonal response of the LAI to drought is mostly overestimated in the DGVM multimodel ensemble compared to the response calculated for the observation-based data. The correlation coefficient values for the multimodel ensemble are as high as 0.76 (annual) over South Africa and 0.98 in the MAM season over the temperate grassland biome. Furthermore, the DGVM model ensemble shows positive biases (3 months or longer) in the simulation of spatial distribution of drought timescales and overestimates the seasonal distribution timescales. The results of this study highlight the areas to target for further development of DGVMs and can be used to improve the models' capability in simulating the drought–vegetation relationship

2009 H1N1 and Seasonal Influenza Immunization Among Pregnant Women: a Comparison of Different Sources of Immunization Information

Validity of prenatal immunization data from different sources has not been assessed. We evaluated prenatal 2009 H1N1 and seasonal influenza (FLU) data obtained from state immunization information systems (IIS), medical record abstraction (MRA), and participant recall using medical care logs (NCS-MCL). 2009 H1N1 and FLU data were obtained from IIS and MRA for 325 pregnant women participating in the National Children\u27s Study at three locations (SD/MN, NC, WI). Women recalled immunizations at first pregnancy visit and at 16-17 and 36 weeks\u27 gestation (NCS-MCL). The proportion of women with vaccine information obtainable from each data source was determined, and proportions immunized as determined using different data sources were compared. IIS data were available for 82%, MRA for 97%, and NCS-MCL for 93% of women. No mention of either vaccine occurred in 29% (range 4-48%) of IIS, 40% of MRA (25-59%), and 59% (43-82%) in NCS-MCL. Best agreement between sources was 2009 H1N1 vaccine in MRA versus IIS [kappa (95% CI) of 0.44 (0.32-0.55)], with poorest agreement for FLU in IIS versus NCS-MCL [0.11 (-0.03 to 0.25)]. IIS was the most sensitive method for identifying women receiving 2009 H1N1 vaccine (92%); MRA was most sensitive for FLU vaccine (81%). IIS provided the most complete and sensitive data for 2009 H1N1 immunizations and MRA the most complete and sensitive data for FLU; IIS data were available for a smaller percent of population than MRA. NCS-MCL was the least sensitive method for identifying vaccinated women

Robust numerical computation of the 3D scalar potential field of the cubic Galileon gravity model at solar system scales

Direct detection of dark energy or modified gravity may finally be within reach due to ultrasensitive instrumentation such as atom interferometry capable of detecting incredibly small scale accelerations. Forecasts, constraints and measurement bounds can now too perhaps be estimated from accurate numerical simulations of the fifth force and its Laplacian field at solar system scales. The cubic Galileon gravity scalar field model (CGG), which derives from the DGP braneworld model, describes modified gravity incorporating a Vainshtein screening mechanism. The nonlinear derivative interactions in the CGG equation suppress the field near regions of high density, thereby restoring general relativity (GR) while far from such regions, field enhancement is comparable to GR and the equation is dominated by a linear term. This feature of the governing PDE poses some numerical challenges for computation of the scalar potential, force and Laplacian fields even under stationary conditions. Here we present a numerical method based on finite differences for solution of the static CGG scalar field for a 2D axisymmetric Sun-Earth system and a 3D Cartesian Sun-Earth-Moon system. The method relies on gradient descent of an integrated residual based on the normal attractive branch of the CGG equation. The algorithm is shown to be stable, accurate and rapidly convergent toward the global minimum state. We hope this numerical study, which can easily be extended to include smaller bodies such as detection satellites, will prove useful to future measurement of modified gravity force fields at solar system scales

Compliance with handwashing at two intensive care units in São Paulo

Handwashing compliance was compared at two medical- surgical intensive care units (ICUs) of a teaching and a non-teaching hospital. The mean compliance was 22.2% and 42.6%, respectively. Respiratory therapists at the non-teaching hospital had the best handwashing compliance (52.6%). Nursing assistants at the teaching hospital had the worst compliance (11.5%). Nursing assistant was the only health-care worker category with a significant difference between the two ICUs (odds ratio = 6.0; 95% confidence interval = 3.83-9.43; p< 0.001).Federal University of São Paulo Division of Infectious Diseases Healthcare Epidemiology CommitteeFederal University of São Paulo Diadema State Hospital Infection Control CommitteeUNIFESP, Division of Infectious Diseases Healthcare Epidemiology CommitteeUNIFESP, Diadema State Hospital Infection Control CommitteeSciEL

State-Level Immunization Information Systems: Potential for Childhood Immunization Data Linkages.

Objectives Sources of immunization data include state registries or immunization information systems (IIS), medical records, and surveys. Little is known about the quality of these data sources or the feasibility of using IIS data for research. We assessed the feasibility of collecting immunization information for a national children\u27s health study by accessing existing IIS data and comparing the completeness of these data against medical record abstractions (MRA) and parent report. Staff time needed to obtain IIS and MRA data was assessed. Methods We administered a questionnaire to state-level IIS representatives to ascertain availability and completeness of their data for research and gather information about data formats. We evaluated quality of data from IIS, medical records, and reports from parents of 119 National Children\u27s Study participants at three locations. Results IIS data were comparable to MRA data and both were more complete than parental report. Agreement between IIS and MRA data was greater than between parental report and MRA, suggesting IIS and MRA are better sources than parental report. Obtaining IIS data took less staff time than chart review, making IIS data linkage for research a preferred choice. Conclusions IIS survey results indicate data can be obtained by researchers using data linkages. IIS are an accessible and feasible child immunization information source and these registries reduce reliance on parental report or medical record abstraction. Researchers seeking to link IIS data with large multi-site studies should consider acquiring IIS data, but may need strategies to overcome barriers to data completeness and linkage