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251.
The SoA conference emphasized that urgent questions posed by society and decision-makers in response to rapid Arctic change require that Arctic research address the broader concepts of sustainability as well as adaptation to and mitigation of interrelated environmental and socioeconomic change. Murray et al. (submitted) explore progress made in this context. The SoA meeting demonstrated significant progress by the Arctic community of scientists and stakeholders in meeting this challenge, as well as the need to better engage the private sector and find more effective ways to partner with relevant research activities outside of the polar regions. 相似文献
252.
I. Made Arcana Bunbun Bundjali M. Hasan Ketut Hariyawati Helen Mariani Shinta Dewi Anggraini Aditya Ardana 《Journal of Polymers and the Environment》2010,18(3):188-195
Poly(urethane-ester) was prepared by polymerization of 4,4′-methylenebis(phenyl isocyanate) (MDI) and prepolymers of ε-caprolactone and 2,2-dimethyl-1,3-propanediol monomers P(CL-DP) with various chain lengths as polyol sources. Characterizations of poly(urethane-ester) were carried out by analysis of functional groups (FTIR), thermal properties (DTA/TGA), mechanical properties (Tensile tester), crystallinity (XRD), and biodegradability. The chain length of prepolymers used in polymerization has a significant effect in properties of poly(urethane-ester) as well as their biodegradability. The formation of poly(urethane-ester) was indicated by the presence of new absorption peaks at wave number of 3,348.2 and 1,596.9 cm?1 for urethane (–NH–) and aromatic groups in chain of polymers, respectively. The increase chain length of prepolymer used in polymerization with 4,4′-methylenebis(phenyl isocyanate) was observed the increase thermal property and crystallinity of poly(urethane-ester). However, the maximum mechanical property and also biodegradability in activated sludge were observed in poly(urethane-ester) prepared by polymerization of 4,4′-methylenebis(phenyl isocyanate) (MDI) and P(CL-DP) prepolymers with DP/CL ratio of 1/20. Apparently, the amorphous parts of polymers are rapidly decomposed by enzymes of microorganisms, so the crystallinity on the whole of poly(urethane-ester) increases after incubation time of 30 days. 相似文献
253.
Helen Kopnina 《Local Environment》2017,22(1):38-48
Studies show a direct relationship between occurrence of asthma and increases of particulate matter in the air. Private transportation is found to be a significant contributor to this problem. The objective of this article is to explore this link between air pollution, asthma and vehicular dependency in order to provide recommendations for health and transport policy. This article focuses on the survey of literature on the relationship between vehicular air pollution and asthma; combining it with the literature on vehicular dependency or ‘car culture’ in the global context and in The Netherlands. This article exposes the imbalance of power between patient groups and polluting industries, and the government failure to protect the weaker party can be explained by corporate pressures. It will be argued that since air pollution is tied to the corporate support for the car industry and vested interests in promoting a ‘car culture’, strategic policy that claims to be concerned with public health should explicitly link the present pattern of mobility to public health. This article concludes with a recommendation for raising environmental health awareness by explicitly linking vehicular dependency to respiratory health through a combination of holistic and citizenship education. 相似文献
254.
255.
Kanwar Devesh Singh Preeti Gangadharan Helen H. Lou Xianchang Li Peyton Richmond 《Journal of the Air & Waste Management Association (1995)》2014,64(11):1328-1340
A computational fluid dynamics (CFD) methodology for simulating the combustion process has been validated with experimental results. Three different types of experimental setups were used to validate the CFD model. These setups include an industrial-scale flare setups and two lab-scale flames. The CFD study also involved three different fuels: C3H6/CH4/Air/N2, C2H4/O2/Ar, and CH4/Air. In the first setup, flare efficiency data from the Texas Commission on Environmental Quality (TCEQ) 2010 field tests were used to validate the CFD model. In the second setup, a McKenna burner with flat flames was simulated. Temperature and mass fractions of important species were compared with the experimental data. Finally, results of an experimental study done at Sandia National Laboratories to generate a lifted jet flame were used for the purpose of validation. The reduced 50 species mechanism, LU 1.1, the realizable k-? turbulence model, and the EDC turbulence–chemistry interaction model were used for this work. Flare efficiency, axial profiles of temperature, and mass fractions of various intermediate species obtained in the simulation were compared with experimental data and a good agreement between the profiles was clearly observed. In particular, the simulation match with the TCEQ 2010 flare tests has been significantly improved (within 5% of the data) compared to the results reported by Singh et al. in 2012. Validation of the speciated flat flame data supports the view that flares can be a primary source of formaldehyde emission.
ImplicationsValidated computational fluid dynamics (CFD) models can be a useful tool to predict destruction and removal efficiency (DRE) and combustion efficiency (CE) under steam/air assist conditions in the face of many other flare operating variables such as fuel composition, exit jet velocity, and crosswind. Augmented with rigorous combustion chemistry, CFD is also a powerful tool to predict flare emissions such as formaldehyde. In fact, this study implicates flares emissions as a primary source of formaldehyde emissions. The rigorous CFD simulations, together with available controlled flare test data, can be fitted into simple response surface models for quick engineering use. 相似文献
256.
Wayne J. Parker Helen Ryan 《Journal of the Air & Waste Management Association (1995)》2013,63(4):582-592
ABSTRACT A field-scale tracer test was conducted to evaluate in-situ ventilation rates in a major collector sewer. The sewer under study was ~11 km long and ranged from 0.61 to 2.1 m in diameter. For the purposes of the tracer testing, the collector was divided into four reaches, each of which was tested individually. The tracer test involved injecting a measured volume of CO gas into a manhole over a short time period. CO concentrations were then measured in the collector headspace at selected manholes along the length of the reach. The technique employed successfully measured average headspace velocities over extended lengths of the collector. In a section that had a relatively stagnant headspace, ~1.1 km of sewer could be evaluated, with substantial tracer loss attributed to losses to manholes. In a section of the sewer with elevated headspace velocities, a section ~7.0 km long was successfully tested with one injection of tracer gas. The velocities observed in the collector varied substantially with time and location in the collector. The lowest velocities measured were in the upstream sections, with a minimum observed value of 3.8 m/min. The highest velocities were observed in the downstream sections, with a maximum value of 31.5 m/min. The presence of a substantial drop structure appeared to reduce the headspace velocity in the upstream reach. In general, there was an increasing trend in gas-phase flows with distance along the length of the collector. Flows at the discharge end of the collector were almost 2 orders of magnitude greater than those at the beginning. 相似文献
257.
Christopher M. Long Helen H. Suh Petros Koutrakis 《Journal of the Air & Waste Management Association (1995)》2013,63(7):1236-1250
ABSTRACT A comprehensive indoor particle characterization study was conducted in nine Boston-area homes in 1998 in order to characterize sources of PM in indoor environments. State-of-the-art sampling methodologies were used to obtain continuous PM2.5 concentration and size distribution particulate data for both indoor and outdoor air. Study homes, five of which were sampled during two seasons, were monitored over week-long periods. Among other data collected during the extensive monitoring efforts were 24hr elemental/organic carbon (EC/OC) particulate data as well as semi-continuous air exchange rates and time-activity information. This rich data set shows that indoor particle events tend to be brief, intermittent, and highly variable, thus requiring the use of continuous instrumentation for their characterization. In addition to dramatically increasing indoor PM25 concentrations, these data demonstrate that indoor particle events can significantly alter the size distribution and composition of indoor particles. Source event data demonstrate that the impacts of indoor activities are especially pronounced in the ultrafine (da < 0.1 um) and coarse (2.5 < da < 10 |um) modes. Among the sources of ultrafine particles characterized in this study are indoor ozone/terpene reactions. Furthermore, EC/OC data suggest that organic carbon is a major constituent of particles emitted during indoor source events. Whether exposures to indoor-generated particles, particularly from large short-term peak events, may be associated with adverse health effects will become clearer when biological mechanisms are better known. 相似文献
258.
Stefanie Ebelt Sarnat Brent A. Coull Pablo A. Ruiz Petros Koutrakis Helen H. Suh 《Journal of the Air & Waste Management Association (1995)》2013,63(2):186-196
Abstract Particle infiltration is a key determinant of the indoor concentrations of ambient particles. Few studies have examined the influence of particle composition on infiltration, particularly in areas with high concentrations of volatile particles, such as ammonium nitrate (NH4NO3). A comprehensive indoor monitoring study was conducted in 17 Los Angeles–area homes. As part of this study, indoor/outdoor concentration ratios during overnight (nonindoor source) periods were used to estimate the fraction of ambient particles remaining airborne indoors, or the particle infiltration factor (FINF), for fine particles (PM2.5), its nonvolatile (i.e., black carbon [BC]) and volatile (i.e., nitrate [NO3 ?]) components, and particle sizes ranging between 0.02 and 10 μm. FINF was highest for BC (median = 0.84) and lowest for NO3 ? (median = 0.18). The low FINF for NO3 ? was likely because of volatilization of NO3 ? particles once indoors, in addition to depositional losses upon building entry. The FINF for PM2.5 (median = 0.48) fell between those for BC and NO3 ?, reflecting the contributions of both particle components to PM2.5. FINF varied with particle size, air-exchange rate, and outdoor NO3 ? concentrations. The FINF for particles between 0.7 and 2 μm in size was considerably lower during periods of high as compared with low outdoor NO3 ? concentrations, suggesting that outdoor NO3 ? particles were of this size. This study demonstrates that infiltration of PM2.5 varies by particle component and is lowest for volatile species, such as NH4NO3. Our results suggest that volatile particle components may influence the ability for outdoor PM concentrations to represent indoor and, thus, personal exposures to particles of ambient origin, because volatilization of these particles causes the composition of PM2.5 to differ indoors and outdoors. Consequently, particle composition likely influences observed epidemiologic relationships based on outdoor PM concentrations, especially in areas with high concentrations of NH4NO3 and other volatile particles. 相似文献
259.
Roger A. Petry Zinaida Fadeeva Olga Fadeeva Helen Hassl?f ?sa Hellstr?m Jos Hermans Yoko Mochizuki Kerstin Sonesson 《Sustainability Science》2011,6(1):83-96
This paper examines how education for sustainable development (ESD) can be concretely advanced using the theoretical approaches
of sustainable consumption and production (SCP) and sustainable livelihoods (SL). Five case examples illustrate a diverse
set of strategic educational interventions focusing on: (1) education of specific organizational actors about these theoretical
frameworks illustrated with case examples (such as SCP training by the United Nations University Institute of Advanced Studies
[UNU-IAS] and CSR-Asia of government and business representatives), (2) regional education strategies focused on production
and consumption in specific sectors (such as the food sector in Sk?ne, Sweden), (3) social learning directed at innovation
for sustainable development (such as competitions of solar boats developed by universities in the region of Friesland, the
Netherlands), (4) education of consumers and firms made possible by the adoption of certification systems affirming SCP and
SL (such as Cradle-to-Cradle certification of a paper company in the Netherlands or the establishment of Fair Trade cities
in Sweden), or (5) reorienting communities to address underutilized productive physical capital within communities (such as
the sharing productive capital project in rural areas of Saskatchewan, Canada). The cases are drawn from the projects that
the UNU-IAS, four of its regional centers of expertise (RCE) on ESD and other affiliates have conducted. In addition to documenting
the educational processes emerging from specific regions, the paper highlights findings related to the success of these projects
and opportunities for further research, including regional and inter-regional approaches. 相似文献
260.
Nydrioti Ioanna Grigoropoulou Helen 《Environmental science and pollution research international》2023,30(8):19918-19930
Environmental Science and Pollution Research - Freshwater is crucial for food supply, as irrigation water and as production or incorporated water in industrial production of consumer goods (e.g.... 相似文献