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Converging–diverging nozzles are common in rocket engine systems to increase the exhaust velocity and improve thrust performance. In this study, we focused on the acceleration of subsonic burned gas without a structural throat via detonation to realize a simple and compact engine. We developed and tested a rotating detonation engine (RDE) without a throat and with a diverging channel (constant diverging angle α=5 deg). Gaseous C2H4 and O2 were used as the propellants, and the mass flow rate ranged from 62 to 134 g/s in the combustion tests under low back-pressure conditions. We measured pressure and thrust, as well as high-speed imaging of self-luminescence of the combustion and imaging of the exhaust plume. The pressure at the exit was less than one-fifth of the maximum pressure in the RDE, significantly below the value for a sonic flow. The results suggested that the exhaust flow was supersonic, with values up to Mach 1.7, without the need of a converging section within the engine. In addition to the estimated Mach number from the measured pressure, the exhaust plume images coherently indicated the existence of supersonic exhaust.

To ensure the leak tightness of SiC/SiC composites cladding, niobium and tantalum have been retained as liner/coating materials for their high melting point, ductility and weldability; however, their chemical compatibility at high temperatures towards SiC remains to be assessed. In the literature, large discrepancies in the composition of the reaction zone and the kinetics were noticed between some metallic liners and SiC. In this work, diffusion couple experiments between Nb and Ta with SiC and SiC/SiC were conducted at high temperatures (1050–1500 °C) to determine the diffusion paths and the reaction kinetics in order to estimate the lifetime of such coatings in nominal conditions. A detailed analysis of the interaction area was conducted as a function of temperature by a combination of experimental characterizations and thermodynamic calculations. No significant difference in the sandwich cladding materials was observed. The interfacial reactivity was found to be strongly higher than expected from literature data. C and Si were evidenced as the main diffusing species in the Nb/SiC and Ta/SiC systems. From the reaction layer thickness extrapolation in gas-cooled fast reactor operating conditions, niobium but especially tantalum have been approved as liner material in hybrid CMC/metal cladding materials from a chemical compatibility point of view.

Single-rod oxidation and quench experiments at very high temperatures in steam atmosphere were conducted with advanced, nuclear grade SiCf/SiC CMC cladding tube segments. A transient experiment was performed until severe local degradation of the sample at maximum temperature of approximately 1845 °C. The degradation was caused by complete consumption of the external CVD-SiC sealcoat, resulting in steam access to the fiber–matrix composite with less corrosion resistance. Approaching these very high temperatures was accompanied by accelerated gas release mainly of H2 and CO2, the formation of surface bubbles and white smoke. Three one-hour isothermal tests at 1700 °C in steam with final water flooding and one three-hour experiment with fast cool-down in Ar atmosphere were run under nominally identical conditions. All isothermally tested samples survived the tests without any macroscopic degradation. The mechanical performance of these quenched clad segments was not significantly affected, while maintaining a high capability to tolerate damages. Despite these harsh exposure conditions, load transfer between SiC fibers and matrix remained efficient, allowing the composites to accommodate deformation.

Objectives To describe the impact of the COVID‐19 pandemic on New York City's (NYC) 9‐1‐1 emergency medical services (EMS) system and assess the efficacy of pandemic planning to meet increased demands. Methods Longitudinal analysis of NYC 9‐1‐1 EMS system call volumes, call‐types, and response times during the COVID‐19 peak‐period (March 16–April 15, 2020) and post‐surge period (April 16–May 31, 2020) compared with the same 2019 periods. Results EMS system received 30,469 more calls from March 16–April 15, 2020 compared with March 16–April 15, 2019 (161,815 vs 127,962; P

(This article belongs to the Special Issue Advanced Composites and Coatings for Nuclear Applications); International audience; In the framework of nuclear applications of SiC/SiC composites, the influence of pyrocarbon interphase texture and thickness on the mechanical behavior both on as processed materials and on irradiated materials is a major concern. Thus, the PyC interphase influence has to be clearly addressed to define its optimal chemical vapor infiltration processing parameters. For this pur-pose, specific 2.5D SiC/SiC composites reinforced with Hi-Nicalon S fibers and with two kind of PyC texture and thickness were produced. Transmission electronic microscopy allowed PyC thickness and microstructure/texture characterizations, whereas push-out and tensile tests were employed as experimental mechanical procedures. Original result is that PyC nature directly in-fluences the Interfacial shear stress and failure mode of the weakest interface, regardless of PyC thickness. Adhesive failure or cohesive failure are highlighted depending on the PyC CVI deposition mechanisms. Similar post irradiation characterizations will be required to assess the role of irradiation on the PyC microstructure/texture evolution and mechanical behaviors of these materials.

The physics of shock-boundary layer interactions (SBLIs) in a supersonic turbine cascade at Mach 2.0 and Reynolds number 395,000, based on the axial chord, is investigated through a wall-resolved large eddy simulation. Special attention is given to the characterization of the low-frequency dynamics of the separation bubbles using flow visualization, spectral analysis, space-time cross correlations, and flow modal decomposition. The mean flowfield shows different shock structures formed on both sides of the airfoil. On the suction side, an oblique shock impinges on the turbulent boundary layer, whereas a Mach reflection interacts with the pressure side boundary layer. The interactions taking place in the present turbine cascade show similarities and discrepancies with respect to more canonical cases. For example, the characteristic frequencies of the shock/bubble motions are comparable to those described in the literature of canonical cases. However, the suction side bubble leads to compression waves that do not coalesce into a separation shock, and a thin bubble forms on the pressure side despite the strong normal shock from the Mach reflection. Instantaneous flow visualizations illustrate elongated streamwise structures on the incoming boundary layers and their interactions with the shocks and separation bubbles. The space-time cross-correlations reveal that the near-wall streaks drive the motion of the suction side separation bubble, which in turn promotes oscillations of the reattachment shock and shear layer flapping. Organized motions in the SBLIs and their corresponding characteristic frequencies and spatial support are identified using proper orthogonal decomposition., Comment: 47 pages, 25 figures. Published in the Physical Review Fluids (https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.7.094602)

International audience; Silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) composites are candidate materials for cladding of light water reactor (LWR) fuels. Loss of fission product gas retention due to the formation of microcrack networks is considered a potential failure mechanism for SiC/SiC-cladded fuels. In this study, a variety of SiC/SiC composite tubes were irradiated with and without an LWR-relevant radial heat flux in the High Flux Isotope Reactor, followed by detailed characterization with X-ray computed tomography (XCT). This first set of XCT data for neutron-irradiated samples confirmed that the internal stresses arising from a combination of temperature gradients and irradiation-induced swelling act as the primary driver for cracking. While the observed cracking patterns varied depending on the tube architectures, the sharp edges of relatively large pores were found to be the common stress concentrator. These findings are useful to help improve the design and manufacturing of SiC/SiC fuel claddings for reduced failure probability.

The harnessing of mechanical power from supersonic flows is constrained by physical limitations and substantial aerodynamic losses. Bladeless axial turbines are a viable alternative to extract power in such harsh conditions without restricting the operating conditions. In this paper, we present a shape optimization of the wavy surface of bladeless turbines to maximize the power extraction, while minimizing convective heat flux and pressure losses. First, a baseline geometry was defined and an experimental campaign was carried out on the baseline wavy surface of the bladeless turbine at supersonic conditions. Pressure, heat flux, and skin friction measurements were compared with the Reynolds averaged Navier–Stokes results. Afterward, an evaluation routine which consisted of the geometry and grid generation, solving, and postprocessing was implemented within a multi-objective optimization routine to maximize the pressure force and minimize heat flux and pressure loss. Finally, a three-dimensional assessment in terms of power, heat load, and pressure drop was performed for the best performing geometry with the commercial solver cfd++ of Metacomp.

International audience; Ceramic matrix composites reinforced by external polymerization of acrylonitrile (ex-PAN) carbon fibers with pyrocarbon (PyC) interphase are attractive materials for thermomechanical applications. Nevertheless, C/SiC composites suffer from a low damage tolerance. A 1600°C thermal pretreatment of the carbon fibers led to an improvement of the mechanical properties of the composites. Even if this heat treatment was seen to modify the fiber microstructure and texture, the changes were not sufficient to explain the observed improvements. The consequences of the thermal treatment on carbon fibers were studied by high resolution transmission electron microscopy and physicochemical analyses. The fiber/matrix debonding was also apprehended by analyzing the interfacial regions of C/SiC composites. The key role of the fiber surface structure on the fiber/matrix (F/M) coupling was highlighted. The microstructural reorganization of the heat-treated fibers surfaces induces a high F/M bonding strength and leads to better damage tolerance for the C/SiC composites.

Objective To determine if oxygen saturation (out‐of‐hospital SpO2), measured by New York City (NYC) 9‐1‐1 Emergency Medical Services (EMS), was an independent predictor of coronavirus disease 2019 (COVID‐19) in‐hospital mortality and length of stay, after controlling for the competing risk of death. If so, out‐of‐hospital SpO2 could be useful for initial triage. Methods A population‐based longitudinal study of adult patients transported by EMS to emergency departments (ED) between March 5 and April 30, 2020 (the NYC COVID‐19 peak period). Inclusion required EMS prehospital SpO2 measurement while breathing room air, transport to emergency department, and a positive severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) reverse transcription polymerase chain reaction test. Multivariable logistic regression modeled mortality as a function of prehospital SpO2, controlling for covariates (age, sex, race/ethnicity, and comorbidities). A competing risk model also was performed to estimate the absolute risks of out‐of‐hospital SpO2 on the cumulative incidence of being discharged from the hospital alive. Results In 1673 patients, out‐of‐hospital SpO2 and age were independent predictors of in‐hospital mortality and length of stay, after controlling for the competing risk of death. Among patients ≥66 years old, the probability of death was 26% with an out‐of‐hospital SpO2 >90% versus 54% with an out‐of‐hospital SpO2 ≤90%. Among patients 90% versus 31% with an out‐of‐hospital SpO2 ≤ 90%. An out‐of‐hospital SpO2 level ≤90% was associated with over 50% decreased likelihood of being discharged alive, regardless of age. Conclusions Out‐of‐hospital SpO2 and age predicted in‐hospital mortality and length of stay: An out‐of‐hospital SpO2 ≤90% strongly supports a triage decision for immediate hospital admission. For out‐of‐hospital SpO2 >90%, the decision to admit depends on multiple factors, including age, resource availability (outpatient vs inpatient), and the potential impact of new treatments.

International audience; The development and availability of a new 3rd generation SiC fiber, the Tyranno SA4 (SA4), are promising for the processing of higher neutron and/or corrosion resistant SiC/SiC composites. Despite its promising properties, especially the higher crystallinity and thermal conductivity than the Hi-Nicalon S fiber, the previous Tyranno SA3 (SA3) reinforcement leads to low damage tolerant SiC/SiC composites, restraining its use as a reinforcement. The latter is the consequence of very high interfacial shear stress, whatever the pyrocarbon interphase thickness. In this work, tubular samples where produced with both reinforcements and with two different pyrocarbon interphase thicknesses for tensile mechanical characterizations to access the potential benefit of the new SA4 fibers. The tensile mechanical properties of SA4 composites are highly enhanced compared to SA3 composites. The low damage tolerance drawback of SA3 composites is solved with high ductility tensile mechanical behavior for SA4-based composites. Tensile mechanical tests also highlight an unusual influence of pyrocarbon interphase thickness on the composites tensile modulus and proportional limit stress. The thinner interphase (≈ 60 nm) is the most interesting for repeatable mechanical properties and induces high proportional limit stress. Unloading █ reloading cycles during tensile mechanical tests also highlight the benefit of this new fiber compare to Hi-Nicalon S. This work demonstrates that the substitution of SA3 by the new SA4 SiC fiber reinforcement in the processing of SiC/SiC composites is a great opportunity for the ceramic matrix composites development and especially for nuclear applications.

Cladding thermal conductivity is an important physical property in assessing the performance of silicon carbide (SiC)-cladded fuels for nuclear reactors. However, there is a significant lack of reliable data, particularly for irradiated materials, because the geometry complicates the measurement. This study investigates the thermal diffusivity of coupons with a curvature, machined from SiC fiber–reinforced SiC matrix composite tubes, with and without neutron irradiation under light water reactor–relevant temperature and dose conditions. The tested materials included full composite and duplex SiC composite tubes. The measurements were conducted using a modern flash diffusivity apparatus. The analyzed area on the specimen during diffusivity testing was reduced for improved measurement accuracy due to sample curvature. Post-irradiation measurements showed that the effects of neutron irradiation on thermal conductivity (e.g. thermal defect resistivity) are different between SiC composite plates versus tubes. The difference was explained by higher matrix density of the tube than the plate. This study provides reliable thermal properties of prototypic SiC composite tubes useful for fuel performance modeling of SiC-based cladding.

Silicon carbide-silicon carbide (SiC/SiC) composites are considered to replace the current zirconium-based cladding materials thanks to their good behavior under irradiation and their resistance under oxidative environments at high temperature. In the present work, a thermodynamic analysis of the UO 2±x /SiC system is performed. Moreover, using two different experimental methods, the chemical compatibility of SiC towards uranium dioxide, with various oxygen contents (UO 2±x ) is investigated in the 1500–1970 K temperature range. The reaction leads to the formation of mainly uranium silicides and carbides phases along with CO and SiO gas release. Knudsen Cell Mass Spectrometry is used to measure the gas release occurring during the reaction between UO 2+x and SiC powders as function of time and temperature. These experimental conditions are representative of an open system. Diffusion couple experiments with pellets are also performed to study the reaction kinetics in closed system conditions. In both cases, a limited chemical reaction is observed below 1700 K, whereas the reaction is enhanced at higher temperature due to the decomposition of SiC leading to Si vaporization. The temperature of formation of the liquid phase is found to lie between 1850

SiC/SiC composites reinforced with Hi-Nicalon S 3rd generation SiC fibers are promising candidates for high temperature aeronautical applications and fuel cladding in nuclear reactors. An original patented process was used to produce SiC/SiC tubular samples for dimensional and tensile mechanical characterizations. The process route is described in detail to further understanding of specific features. SiC/SiC samples show a low porosity and excellent geometrical tolerance. Highly reproducible tensile mechanical behavior is observed with good mechanical failure characteristics. Some specific features were highlighted during mechanical characterizations with loading/unloading sequences. For instance, an original mechanical behavior was observed before the onset of matrix multicracking (deviation from linearity). To our knowledge, it is the first time that this kind of behavior has been detected on SiC/SiC composites, due to the processing route leading to the microstructure of specific samples.

SiC/SiC composites have aroused interest for various nuclear applications. For example, the use of SiC/SiC components in Sodium-cooled Fast Reactors in replacement of steel wrapper tubes should improve the safety. However, the chemical compatibility between the liquid sodium and SiC or SiC/SiC composites and its effect on their mechanical properties remain unknown. Corrosion tests were conducted on CVD SiC and both undamaged and pre-damaged SiC/SiC in liquid sodium at 823 K up to 2000 h in two different sodium batches, a purified and an oxygen-rich. No strong corrosion of the CVD SiC and no degradation of the mechanical properties of SiC/SiC composites were observed in both conditions, even with mechanical pre-damaging prior to immersion. A strong increase in ultimate tensile strength was highlighted after exposure, only for the undamaged samples. This phenomenon is attributed to the healing by liquid sodium of the microcracks generated during the manufacturing process.

This paper examines how migrating Jamaicans were constructed as ‘worthy’ or ‘unworthy’ of Jamaican diasporic membership in the early years of statehood, to demonstrate the role of nationalist cultural repertoires in constructing particular diasporic imaginaries. I conduct a discourse analysis of Jamaica's national newspaper, The Daily Gleaner, between 1962 and 1966, a period encompassing crucial transitions in Jamaican migration movements and from colony to statehood. I argue that tropes of respectability present in Afro-creole nationalist ideology form the cultural repertoires used to distinguish migrants' actions as worthy or unworthy of national membership. These distinctions specify who ‘counts’ as part of the diaspora and how migrants of different social positions may claim and articulate their membership.

SiC/SiC composites reinforced with 3rd generation SiC fibers (Hi-Nicalon S and Tyranno SA3 fibers) are promising candidates for thermomechanical applications in high technology industries. Both composites exhibited a pseudo-ductile mechanical behavior but the HNS/PyC/SiC composite reaches higher failure strains than TSA3/PyC/SiC ones. The mechanical behavior of SiC/SiC composites is linked to the way PyC is bonded to the fiber surface. Analyses have shown that these interactions and the Fiber/Matrix debonding behavior depend strongly on the nature of the carbon on the SiC fiber surface, which is different according to the SiC fiber. In order to understand the mechanism governing the chemical adhesion at the PyC/SiC fiber interface, the formation, the chemistry and the structure of the surface carbon layer were studied. Understanding the origin of this carbon has allowed elucidating the local interaction mechanisms of the studied SiC/SiC composites.

Background Our community-based clinic decided to implement routine screening for anorectal Gonorrhea (GC) and Chlamydia (CT) for patients undergoing HRA for anal cancer prevention, due to high risk for asymptomatic GC and CT among our patient population (predominantly HIV+ MSM in NYC) and the impact undiagnosed GC/CT infection may have on recovery after biopsy or ablation of HPV-related lesions. In 2016, the CDC reported a prevalence of anorectal GC and CT of 0.146% and 0.497% in the general population nationally, and 12.1% and 12.7% in MSM in NYC clinics in the STD Surveillance Network. Methods Retrospective chart review for all HRA completed in 2017 using associated CPT and testing codes. Results 839 HRA procedures were done in 2017. Of the anorectal NAATs performed, 6.6% were positive for either GC and/or CT (4% for GC and 3% for CT). Conclusions Implementing routine screening for anorectal GC/CT at every HRA for HPV-related disease revealed a prevalence of concurrent anorectal GC and/or CT infection well above national prevalence for the general population, though at a lower rate than anorectal GC/CT among MSM seeking screening or treatment in NYC DOH clinics. We were unable to make conclusions about how treating these incidental infections impacted recovery after the procedure, as this was outside the scope of this limited chart review. But the prevalence of GC/CT infection discovered in this analysis supports the importance of adding routine GC/CT screening for all patients undergoing HRA for the diagnosis or treatment of HPV-related anal neoplasia.

Silicon carbide ceramics are really appreciated in energy applications, especially when extreme environments are involved. Their reliability and thermomechanical performances beyond 1000°C are higher than that of superalloys, therefore they may significantly contribute to the reduction of Critical Raw Materials use, which is a crucial point for sustainability issues. The examples discussed in the present paper are taken from European projects, in the field of nuclear energy (IV gen fission nuclear reactors) and renewable energy production (Concentrated Solar Power) and demonstrate a common approach based on optimizing and assessing the ceramic materials, considering current international standards, but also prenormative research and accelerated ageing tests in expected working environments. In this way, together with a simultaneous process implementation for the production of components in the size and geometry required for the applications, high target TRL (5-7) can be demonstrated, creating the competencies, the methods and the results needed for subsequent industrialisation. İ 2018 IEEE.

International audience; The graphene is a material obtained when carbon atoms form large planar molecules. Well organized, large graphene molecules stacked ontop each other convey to graphene particularly interesting properties useful in nuclear industry. Understanding how the organization on the molecular scale influences the mechanical properties of the material is a key element in the material manufacturing process. In this scope, features like local orientation and length have already been largely explored in the literature. This paper brings a new feature evaluating the number of plans stacked ontop each other and the length of this stacking. It allows obtaing other features such as the overall rate of organization or locality and preferential orientation. These informations, synthesized in the form of histograms provides a key information in the processus the material design. Experimental results obtained on images taken by an electronic scanning microscope are presented to illustrate the proposed method.

ObjectiveWe aimed to evaluate emergency medical services (EMS) data as disaster metrics and to assess stress in surrounding hospitals and a municipal network after the closure of Bellevue Hospital during Hurricane Sandy in 2012.MethodsWe retrospectively reviewed EMS activity and call types within New York City’s 911 computer-assisted dispatch database from January 1, 2011, to December 31, 2013. We evaluated EMS ambulance transports to individual hospitals during Bellevue’s closure and incremental recovery from urgent care capacity, to freestanding emergency department (ED) capability, freestanding ED with 911-receiving designation, and return of inpatient services.ResultsA total of 2,877,087 patient transports were available for analysis; a total of 707,593 involved Manhattan hospitals. The 911 ambulance transports disproportionately increased at the 3 closest hospitals by 63.6%, 60.7%, and 37.2%. When Bellevue closed, transports to specific hospitals increased by 45% or more for the following call types: blunt traumatic injury, drugs and alcohol, cardiac conditions, difficulty breathing, “pedestrian struck,” unconsciousness, altered mental status, and emotionally disturbed persons.ConclusionsEMS data identified hospitals with disproportionately increased patient loads after Hurricane Sandy. Loss of Bellevue, a public, safety net medical center, produced statistically significant increases in specific types of medical and trauma transports at surrounding hospitals. Focused redeployment of human, economic, and social capital across hospital systems may be required to expedite regional health care systems recovery. (Disaster Med Public Health Preparedness. 2016;10:333–343)

Abstract In Book II of the Republic (370c-372d), Socrates briefly depicts a city where each inhabitant contributes to the welfare of all by performing the role for which he or she is naturally suited. Socrates calls this city the ‘true city’ and the ‘healthy one’. Nearly all commentators have argued that Socrates’ praise of the city cannot be taken at face value, claiming that it does not represent Socrates’ preferred community. The point of this paper is to argue otherwise. The claim is that Socrates genuinely believes the city is a healthy and desirable city, and that he believes that the First City (the so-called ‘city of pigs’) is in fact superior to the Kallipolis.

To overcome the problems of a current hydrogen storage technology, EnerFuel has invented a proprietary chemical process, which produces hydrogen through a new chemical reaction of sodium borohydride. Based on the new chemistry, EnerFuel developed portable hydrogen storage and generator system. This device has 7.03 kWh total hydrogen content and is designed to provide hydrogen on demand for 1W to 60 W fuel cells. However, the simple system design allows for easy scaling up or down hydrogen content and flow rates. This specific storage is designed to be used on board of a remote surveillance system produced by EnerFuel. The storage operates at low pressure and in a wide temperature range from less than 0{degree sign}C to 80{degree sign}C. A new storage is a safe and reliable supply of hydrogen. The hydrogen is generated and present only when required by fuel cell. As a result of the advanced design, the hydrogen volumetric capacity is 40.8 g/L, and gravimetric capacity is 35.2 g/kg.

Most extreme heat studies relate outdoor weather conditions to human morbidity and mortality. In developed nations, individuals spend ~90% of their time indoors. This pilot study investigated the indoor environments of people receiving emergency medical care in New York City, NY, U.S., from July to August 2013. The first objective was to determine the relative influence of outdoor conditions as well as patient characteristics and neighborhood sociodemographics on indoor temperature and specific humidity (N = 764). The second objective was to determine whether cardiovascular or respiratory cases experience hotter and more humid indoor conditions as compared to controls. Paramedics carried portable sensors into buildings where patients received care to passively monitor indoor temperature and humidity. The case-control study compared 338 respiratory cases, 291 cardiovascular cases, and 471 controls. Intuitively, warmer and sunnier outdoor conditions increased indoor temperatures. Older patients who received emergency care tended to occupy warmer buildings. Indoor-specific humidity levels quickly adjusted to outdoor conditions. Indoor heat and humidity exposure above a 26 °C threshold increased (OR: 1.63, 95% CI: 0.98-2.68, P = 0.056), but not significantly, the proportion of respiratory cases. Indoor heat exposures were similar between cardiovascular cases and controls.

Introduction:On 14 August 2003, New York City and a large portion of the northeastern United States experienced the largest blackout in the history of the country. An analysis of such a widespread disaster on emergency medical service (EMS) operations may assist in planning for and managing such disasters in the future.Methods:A retrospective review of all EMS activity within New York City's 9-1-1 emergency telephone system during the 29 hours during which all or parts of the city were without power (16:11 hours (h) on 14 August 2003 until 21:03 h on 15 August 2003) was performed. Control periods were established utilizing identical time periods during the five weeks preceding the blackout.Results:Significant increases were identified in the overall EMS demand (7,844 incidents vs. 3,860 incidents; pConclusions:The citywide blackout resulted in dramatic changes in the demands upon the EMS system of New York City, the types of patients for whom EMS providers were assigned to provide care, and the dispositions for those assignments. During this time of increased, system-wide demand, the use of cross-trained firefighter and first-responder engine companies resulted in improved response times to cardiac arrest patients. Finally, the ability of the EMS dispatch center to process the increased requests for EMS assistance proved to be the rate-limiting step in responding to these emergencies.These findings will prove useful in planning for future blackouts or any disaster that may broadly impact the infrastructure of a city.

We sought to evaluate the accuracy and speed for the triage of multiple patients during a disaster drill by Emergency Medical Service (EMS) personnel. During a disaster drill (train collision with blast injury and chemical release), the accuracy and speed of triage of 130 patient-actors by the Fire Department of New York City (FDNY) EMS personnel was evaluated using the Simple Triage and Rapid Treatment (START) triage system. All EMS personnel had been previously trained in START, but refresher training was not administered before the drill. Overall triage accuracy was 78%. In patients that had additional changes in their status during the triage process (injects), 62% were retriaged appropriately. Because of security and decontamination procedures, triage at the triage/treatment area began 40 minutes after the drill commenced. It took 2 hours and 38 minutes to completely clear the scene of all patients. On average, the time from the start of triage to transport was 1 hour and 2 minutes. Despite the fact that triage is a skill practiced by every EMS system in the country on a daily basis, few studies regarding triage accuracy are available. Limited data suggest that the triage accuracy rates using different triage strategy algorithms are approximately 45% to 55%. During this drill, FDNY-EMS triage accuracy using the START system exceeded these expectations. This study provides insight as to the triage experience of a large urban EMS system operating at a disaster drill.

Vehicle emissions can constitute a major share of ambient concentrations of many volatile organic compounds (VOCs) and other air pollutants in urban areas. Especially high concentrations may occur at curbsides, vehicle cabins, and other microenvironments. Such levels are not reflected by monitoring at fixed sites. This study reports on measurements of VOCs made from buses and cars in Detroit, MI. A total of 74 adsorbent tube samples were collected on 40 trips and analyzed by GC-MS for 77 target compounds. Three bus routes, selected to include residential, commercial and heavily industrialized areas, were sampled simultaneously on four sequential weeks during morning and afternoon rush hour periods. Nineteen compounds were regularly detected and quantified, the most prevalent of which included hexane/2-methyl pentane (15.6±5.8 μg m−3), toluene (10.2±7.9 μg m−3), m,p-xylene (6.8±4.7 μg m−3), benzene (4.5±3.0 μg m−3), 1,2,4-trimethylbenzene (4.0±2.6 μg m−3), o-xylene (2.2±1.6 μg m−3), and ethylbenzene (2.1±1.5 μg m−3). VOC levels in bus interiors and outdoor levels along the roadway were similar. Despite the presence of large industrial sources, route-to-route variation was small, but temporal variation was large and statistically significant. VOC compositions and trends indicate the dominance of vehicle sources over the many industrial sources in Detroit with the possible exceptions of styrene and several chlorinated VOCs. In-bus levels exceeded concentrations at fixed site monitors by a factor of 2–4. VOC concentrations in Detroit traffic are generally comparable to levels measured elsewhere in the US and Canada, but considerably lower than measured in Asia and Europe.