32 research outputs found
Inverse Fluid Convection Problems in Enclosures
Efficiency, security, and reliability of industrial and domestic processes essentially depend on the deep understanding of their actual processes of fluid flow and heat transfer. Actual processes of fluid flow control and measurements need the development of effect-cause inverse modeling. Extensive investigations on the effect-cause inverse modeling could effectively enhance the efficiency, security, and reliability of these industrial and domestic fluid flow processes
Determinants of personal exposure to fine particulate matter (PM2.5) adult subjects in Hong Kong
Personal monitoring for fine particulate matter (PM2.5) was conducted for adults (48 subjects, 18-63 years of age) in Hong Kong during the summer and winter of 2014-2015. All filters were analyzed for PM2.5 mass and constituents (including carbonaceous aerosols, water-soluble ions, and elements). We found that season (p = 0.02) and occupation (p < 0.001) were significant factors affecting the strength of the personal-ambient PM2.5 associations. We applied mixed-effects models to investigate the determinants of personal exposure to PM2.5 mass and constituents, along with within- and between-individual variance components. Ambient PM2.5 was the dominant predictor of (R-2 = 0.12-0.59, p < 0.01) and the largest contributor (>37.3%) to personal exposures for PM2.5 mass and most components. For all subjects, a one-unit (2.72 mu g/m(3)) increase in ambient PM2.5 was associated with a 0.75 mu g/m(3) (95% CI: 0.59-0.94 mu g/m(3)) increase in personal PM2.5 exposure. The adjusted mixed-effects models included information extracted from individual's activity diaries as covariates. The results showed that season, occupation, time indoors at home, in transit, and cleaning were significant determinants for PM2.5 components in personal exposure (R-beta(2) = 0.06-0.63, p < 0.05), contributing to 3.0-70.4% of the variability. For onehour extra time spent at home, in transit; and cleaning an average increase of 1.7-3.6% (ammonium, sulfate, nitrate, sulfur), 2.7-12.3% (elemental carbon, ammonium, titanium, iron), and 8.7-19.4% (ammonium, magnesium ions, vanadium) in components of personal PM2.5 were observed, respectively. In this research, the within-individual variance component dominated the total variability for all investigated exposure data except PM2.5 and EC. Results from this study indicate that performing long-term personal monitoring is needed for examining the associations of mass and constituents of personal PM2.5 with health outcomes in epidemiological studies by describing the impacts of individual-specific data on personal exposures. (C) 2018 Elsevier B.V. All rights reserved
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
Imaging biomarker roadmap for cancer studies.
Imaging biomarkers (IBs) are integral to the routine management of patients with cancer. IBs used daily in oncology include clinical TNM stage, objective response and left ventricular ejection fraction. Other CT, MRI, PET and ultrasonography biomarkers are used extensively in cancer research and drug development. New IBs need to be established either as useful tools for testing research hypotheses in clinical trials and research studies, or as clinical decision-making tools for use in healthcare, by crossing 'translational gaps' through validation and qualification. Important differences exist between IBs and biospecimen-derived biomarkers and, therefore, the development of IBs requires a tailored 'roadmap'. Recognizing this need, Cancer Research UK (CRUK) and the European Organisation for Research and Treatment of Cancer (EORTC) assembled experts to review, debate and summarize the challenges of IB validation and qualification. This consensus group has produced 14 key recommendations for accelerating the clinical translation of IBs, which highlight the role of parallel (rather than sequential) tracks of technical (assay) validation, biological/clinical validation and assessment of cost-effectiveness; the need for IB standardization and accreditation systems; the need to continually revisit IB precision; an alternative framework for biological/clinical validation of IBs; and the essential requirements for multicentre studies to qualify IBs for clinical use.Development of this roadmap received support from Cancer Research UK and the Engineering and Physical Sciences Research Council (grant references A/15267, A/16463, A/16464, A/16465, A/16466 and A/18097), the EORTC Cancer Research Fund, and the Innovative Medicines Initiative Joint Undertaking (grant agreement number 115151), resources of which are composed of financial contribution from the European Union's Seventh Framework Programme (FP7/2007-2013) and European Federation of Pharmaceutical Industries and Associations (EFPIA) companies' in kind contribution
Public Health Impacts of Combustion Emissions in the United Kingdom
Combustion emissions are a major contributor to degradation
of
air quality and pose a risk to human health. We evaluate and apply
a multiscale air quality modeling system to assess the impact of combustion
emissions on UK air quality. Epidemiological evidence is used to quantitatively
relate PM<sub>2.5</sub> exposure to risk of early death. We find that
UK combustion emissions cause ∼13,000 premature deaths in the
UK per year, while an additional ∼6000 deaths in the UK are
caused by non-UK European Union (EU) combustion emissions. The leading
domestic contributor is transport, which causes ∼7500 early
deaths per year, while power generation and industrial emissions result
in ∼2500 and ∼830 early deaths per year, respectively.
We estimate the uncertainty in premature mortality calculations at
−80% to +50%, where results have been corrected by a low modeling
bias of 28%. The total monetized life loss in the UK is estimated
at £6–62bn/year or 0.4–3.5% of gross domestic product.
In Greater London, where PM concentrations are highest and are currently
in exceedance of EU standards, we estimate that non-UK EU emissions
account for 30% of the ∼3200 air quality-related deaths per
year. In the context of the European Commission having launched infringement
proceedings against the UK Government over exceedances of EU PM air
quality standards in London, these results indicate that further policy
measures should be coordinated at an EU-level because of the strength
of the transboundary component of PM pollution
Developing a high-resolution wind map for a complex terrain with a coupled MM5/CALMET system
Quantifying the climate impacts of albedo changes due to biofuel production: a comparison with biogeochemical effects
Lifecycle analysis is a tool widely used to evaluate the climate impact of greenhouse gas emissions attributable to the production and use of biofuels. In this paper we employ an augmented lifecycle framework that includes climate impacts from changes in surface albedo due to land use change. We consider eleven land-use change scenarios for the cultivation of biomass for middle distillate fuel production, and compare our results to previous estimates of lifecycle greenhouse gas emissions for the same set of land-use change scenarios in terms of CO _2 e per unit of fuel energy. We find that two of the land-use change scenarios considered demonstrate a warming effect due to changes in surface albedo, compared to conventional fuel, the largest of which is for replacement of desert land with salicornia cultivation. This corresponds to 222 gCO _2 e/MJ, equivalent to 3890% and 247% of the lifecycle GHG emissions of fuels derived from salicornia and crude oil, respectively. Nine of the land-use change scenarios considered demonstrate a cooling effect, the largest of which is for the replacement of tropical rainforests with soybean cultivation. This corresponds to − 161 gCO _2 e/MJ, or − 28% and − 178% of the lifecycle greenhouse gas emissions of fuels derived from soybean and crude oil, respectively. These results indicate that changes in surface albedo have the potential to dominate the climate impact of biofuels, and we conclude that accounting for changes in surface albedo is necessary for a complete assessment of the aggregate climate impacts of biofuel production and use
Association between ambient air pollutants and upper respiratory tract infection and pneumonia disease burden in Thailand from 2000 to 2022: a high frequency ecological analysis
Abstract Background A pertinent risk factor of upper respiratory tract infections (URTIs) and pneumonia is the exposure to major ambient air pollutants, with short term exposures to different air pollutants being shown to exacerbate several respiratory conditions. Methods Here, using disease surveillance data comprising of reported disease case counts at the province level, high frequency ambient air pollutant and climate data in Thailand, we delineated the association between ambient air pollution and URTI/Pneumonia burden in Thailand from 2000 – 2022. We developed mixed-data sampling methods and estimation strategies to account for the high frequency nature of ambient air pollutant concentration data. This was used to evaluate the effects past concentrations of fine particulate matter (PM2.5), sulphur dioxide (SO2), and carbon monoxide (CO) and the number of disease case count, after controlling for the confounding meteorological and disease factors. Results Across provinces, we found that past increases in CO, SO2, and PM2.5 concentration were associated to changes in URTI and pneumonia case counts, but the direction of their association mixed. The contributive burden of past ambient air pollutants on contemporaneous disease burden was also found to be larger than meteorological factors, and comparable to that of disease related factors. Conclusions By developing a novel statistical methodology, we prevented subjective variable selection and discretization bias to detect associations, and provided a robust estimate on the effect of ambient air pollutants on URTI and pneumonia burden over a large spatial scale
Air Quality and Climate Impacts of Alternative Bus Technologies in Greater London
The environmental impact of diesel-fueled
buses can potentially
be reduced by the adoption of alternative propulsion technologies
such as lean-burn compressed natural gas (LB-CNG) or hybrid electric
buses (HEB), and emissions control strategies such as a continuously
regenerating trap (CRT), exhaust gas recirculation (EGR), or selective
catalytic reduction with trap (SCRT). This study assessed the environmental
costs and benefits of these bus technologies in Greater London relative
to the existing fleet and characterized emissions changes due to alternative
technologies. We found a >30% increase in CO<sub>2</sub> equivalent
(CO<sub>2</sub>e) emissions for CNG buses, a <5% change for exhaust
treatment scenarios, and a 13% (90% confidence interval 3.8–20.9%)
reduction for HEB relative to baseline CO<sub>2</sub>e emissions.
A multiscale regional chemistry-transport model quantified the impact
of alternative bus technologies on air quality, which was then related
to premature mortality risk. We found the largest decrease in population
exposure (about 83%) to particulate matter (PM<sub>2.5</sub>) occurred
with LB-CNG buses. Monetized environmental and investment costs relative
to the baseline gave estimated net present cost of LB-CNG or HEB conversion
to be 73 million to 36 million (102 million), respectively, while EGR or SCRT estimated
net present costs were 7 million to 15 million (23 million), respectively