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231.
Recent research has demonstrated that nitrogen oxides are transformed to nitrogen acids in indoor environments, and that significant concentrations of nitrous acid are present in indoor air. The purpose of the study reported in this paper has been to investigate the sources, chemical transformations and lifetimes of nitrogen oxides and nitrogen acids under the conditions existing in buildings. An unoccupied single family residence was instrumented for monitoring of NO, NO2, NOy, MONO, HNO3, CO, temperature, relative humidity, and air exchange rate. For some experiments, NO2 and HONO were injected into the house to determine their removal rates and lifetimes. Other experiments investigated the emissions and transformations of nitrogen species from unvented natural gas appliances. We determined that HONO is formed by both direct emissions from combustion processes and reaction of NO2 with surfaces present indoors. Equilibrium considerations influence the relative contributions of these two sources to the indoor burden of HONO. We determined that the lifetimes of trace nitrogen species varied in the order NO ~ HONO > NO2 >HNO3. The lifetimes with respect to reactive processes are on the order of hours for NO and HONO, about an hour for NO2, and 30 minutes or less for HNO3. The rapid removal of NO2 and long lifetime of HONO suggest that HONO may represent a significant fraction of the oxidized nitrogen burden in indoor air.  相似文献   
232.
In Europe, sustainable development (SD) is pursued with not one but two overarching strategies, i.e., the so-called Lisbon and SD strategies. While the Lisbon Strategy is a genuinely European response to global economic and social pressures, SD strategies are national efforts corresponding with international (mainly United Nations) guidance to better coordinate and integrate economic, social and, in particular, environmental policies. The present paper explores the vertical coordination and coherence of the two pan-European strategies. After reviewing the international background of SD strategies and the EU origins of the Lisbon strategy, the paper characterizes and compares the governance architectures of the two strategies. With a solid background on how vertical policy integration functions in the two processes, the paper then shows how this affects the coherence of respective strategy structures and monitoring indicators. Based on an extensive empirical stocktaking study of the objectives and indicators in Lisbon and SD strategies across Europe it is shown that, despite the stronger European coordination through the Open Method of Coordination, the Lisbon process entailed only slightly more coherent national strategies than international guidance did in the context of SD strategies. Thus, the paper concludes that the influence international organizations such as the UN and the OECD have on national policy-making must not be underestimated.  相似文献   
233.
ABSTRACT

The chemical speciation of Ni in fly ash produced from ~0.85 wt % S residual (no. 6 fuel) oils in laboratory (7 kW)- and utility (400 MW)-scale combustion systems was investigated using X-ray absorption fine structure (XAFS) spectroscopy, X-ray diffraction (XRD), and acetate extraction [1 M NaOAc-0.5 M HOAc (pH 5) at 25 °C]-anodic stripping voltammetry (ASV). XAFS was also used to determine the Ni speciation of ambient particulate matter (PM) sampled near the 400-MW system. Based on XAFS analyses of bulk fly ash and their corresponding acetate extraction residue, it is estimated that >99% of the total Ni (0.38 wt %) in the experimentally produced fly ash occurs as NiSO4-xH2O, whereas >95% of the total Ni (1.70 and 2.25 wt %) in two fly ash samples from the 400-MW system occurs as NiSO4-xH2O and Ni-bearing spinel, possibly NiFe2O4. Spinel was also detected using XRD. Acetate extracts most of the NiSO4-xH2O and concentrates insoluble NiFe2O4 in extraction residue. Similar to fly ash, ambient PM contains NiSO4-xH2O and NiFe2O4;

however, the proportion of NiSO4-xH2O relative to NiFe2O4 is much greater in the PM. Results from this and previous investigations indicate that residual oil ash produced in the 7-kW combustion system lack insoluble Ni (e.g., NiFe2O4) but are enriched in soluble NiSO4-xH2O relative to fly ash from utility-scale systems. This difference in Ni speciation is most likely related to the lack of additive [e.g., Mg(OH)2] injection and residence time in the 7-kW combustion system.  相似文献   
234.
Data points intensively sampling 46 North American biomes were used to predict the geographic distribution of biomes from climate variables using the Random Forests classification tree. Techniques were incorporated to accommodate a large number of classes and to predict the future occurrence of climates beyond the contemporary climatic range of the biomes. Errors of prediction from the statistical model averaged 3.7%, but for individual biomes, ranged from 0% to 21.5%. In validating the ability of the model to identify climates without analogs, 78% of 1528 locations outside North America and 81% of land area of the Caribbean Islands were predicted to have no analogs among the 46 biomes. Biome climates were projected into the future according to low and high greenhouse gas emission scenarios of three General Circulation Models for three periods, the decades surrounding 2030, 2060, and 2090. Prominent in the projections were (1) expansion of climates suitable for the tropical dry deciduous forests of Mexico, (2) expansion of climates typifying desertscrub biomes of western USA and northern Mexico, (3) stability of climates typifying the evergreen-deciduous forests of eastern USA, and (4) northward expansion of climates suited to temperate forests, Great Plains grasslands, and montane forests to the detriment of taiga and tundra climates. Maps indicating either poor agreement among projections or climates without contemporary analogs identify geographic areas where land management programs would be most equivocal. Concentrating efforts and resources where projections are more certain can assure land managers a greater likelihood of success.  相似文献   
235.
Effective and efficient information dissemination is crucial for a successful management of coasts and beaches. Almost all coastal management activities use Internet portals to provide electronic accessibility of data and information. In this respect, we have analyzed web tracking data and costs to investigate the effectiveness and efficiency of two coastal management web portals. Indicators for the visiting quality, the volume and characteristics of the information flow and the associated costs were combined. The results show that mainly professional users were attracted by the two investigated online coastal management information offers. Furthermore, the coastal management contents were mainly relevant on regional scale. The results indicate that it is not enough to provide various information, instead it further needs also efforts to disseminate this information to a broader public. Specific preparation and presentation of information for the target groups would lead to an active dissemination process. The investigation of the costs shows that an increasing efficiency of information dissemination via the Internet goes together with the long term use of the information infrastructure. Therefore large coastal management web portals need runtimes of several years. The applied method combined and simplified actual used web analytic methods to allow valuable insights into the information dissemination of coastal management web portals. In this way the method can be used to help coastal decision makers or other practitioners to screen their web presence in the background of information supply and demand for all visitor groups they want to reach.  相似文献   
236.
Although the passion that people demonstrate at work would appear to be a topic of considerable interest and importance to organizational scholars and practitioners, we know virtually nothing about it. In response, we introduce the work passion construct, discuss what we currently understand, and provide needed directions for future research. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
237.
美国环境保护部负责评估超过10 000种化学物质的内分泌活动,而合理的实现评估不能仅仅利用体内化验。因此,使用以特定的内分泌系统为目标测定的体外高通量(HTP)数据提出了化学物质体内化验优先原则。最近聚焦于潜在雌激素化学物质—特别是关于能够激活雌激素受体α(ERα)的化学物质的研究工作大致证实了该方法的可行性。然而,该方法存在一个主要的不确定性,那就是基于哺乳动物(主要是人类)的HTP ER化验的优先级是否能够准确地反映chemical-ERα在非哺乳类物种中潜在的相互作用。这里我们对以下几方面进行了全面分析,包括基于ERs结构属性、体外绑定和ERα反式激活数据的相关信息研究chemical-ERα交互作用的跨物种相似性,以及一系列化学物质对体内雌激素信号通路的影响。总的来说,这种综合分析表明,在哺乳动物系统中具有中度到高度雌激素效能的化学物质在非哺乳类脊椎动物中同样是优先级的化学物质。然而,由于缺乏对可能的ERαorthologues的生物作用的了解,优先级方法在多大程度上能够适用于无脊椎动物是不确定的。进一步比较分析鱼类和爬行动物的体外数据表明基于哺乳类的试验可能不会有效地获取在所有脊椎动物门类中ERα与低亲和力的化学物质的交互作用。
精选自Gerald T. Ankley, Carlie A. LaLone, L. Earl Gray, Daniel L. Villeneuve, Michael W. Hornung. Evaluation of the Scientific Underpinnings for Identifying Estrogenic Chemicals in Non-Mammalian Taxa using Mammalian Test Systems. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2806–2816, November 2016. DOI: 10.1002/etc.3456
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3456/full
  相似文献   
238.
Abstract

Objective: Though the mortality rate for motor vehicle collisions (MVCs) has been decreasing since the 1960s with the advent of the first federal seat belt laws in 1968, MVC remains a leading cause of death for individuals aged 1 to 44 years. The purpose of this study is to examine the effects of frontal (FABs) and side airbags (SABs) and electronic stability control (ESC) on the components of the MVC mortality rate.

Methods: The MVC mortality rate from 1994 to 2015 was separated into its components of exposure of vehicles, exposure of travel, collision density, injury incidence, and case fatality rate. Year was categorized on the availability of safety technology in vehicles: 1994–1997 (first-generation FABs mandated), 1998–2001 (sled-certified, second-generation FABs mandated), 2002–2006 (increasing prevalence of SABs and ESC), 2007–2011 (advanced airbags mandated), and 2012–2015 (ESC mandated, SAB in over 90% of vehicles, introduction of advanced safety systems). Relative contributions (RCs) of the components to changes in the MVC-related mortality rate were calculated as the absolute value of the component’s beta coefficient divided by the sum of the absolute values of all components’ beta coefficients. Negative binomial regression–estimated rate ratios (RRs) for the changes in the rate of each component by year category compared to the prior year category.

Results: Significant decreases in the MVC mortality rate were observed for 2007–2011 and 2012–2015. The decrease in 2007–2011 was due in most part to an 18% decrease in the injury incidence (RR?=?0.82, P?<?.0001, RC?=?63%), though there was a noted contribution by the decrease in vehicle miles traveled (RR?=?0.95, P?<?.0001, RC?=?15%). The continued decrease in mortality in 2012–2015 was due is most part to the 10% decreased case fatality rate (RR?=?0.90, P?<?.0001, RC?=?66%) because there was no significant change in the vehicle miles traveled and injury incidence.

Conclusions: The results of this study highlight the effects of vehicle safety technologies on the MVC-related mortality rate and can help direct prevention efforts. Through the study period, there was no meaningful contribution to decreases in the MVC-related mortality rate due to components related to exposure (i.e., vehicles per population and the rate of vehicle miles traveled), suggesting that prevention efforts at decreasing exposure prevalence would have little effect on the MVC-related mortality rate. Instead, prevention efforts should continue to focus on event-phase methods to decrease injury occurrence and mitigate injury severity during the collision.  相似文献   
239.
Hydro-economic models can measure the economic effects of different reservoir operating rules, environmental restrictions, maintenance of ecosystems, technical constraints, institutional constraints, land use change, and climate change. To determine the optimal economic water allocation, for its main uses in the sub-middle of the São Francisco River Basin, a hydro-economic optimization model was developed and applied. Demand curves were used rather than fixed requirements for water resources. The results show that operation rules of reservoirs and institutional constraints, such as priorities for human consumption, have high impacts on costs and benefits of the principal economic uses in the study area. Especially, costs of environmental demands, like minimum ecological river flow, have high impacts on the water resource management. Scarcity costs of irrigation users associated with maintaining ecosystems and environmental constraints are particularly significant. The results from this study provide a better understanding of the water trade-offs for future policymaking and efficient water management. Policymaking for the water resources should consider the food-water-energy-environment nexus at a regional scale to minimize environmental and economic cost under water scarcity and land use change.  相似文献   
240.
This paper investigates the influence of consumptionrisk on incentives for soil conservation. A dynamicmodel is developed to show how investments in soilconservation affect consumption risk on small farmsand how these risks influence incentives for soilconservation. Model predictions are compared withobserved patterns of soil conservation adoption in thePhilippines. Results show that on small farms the riskof consumption shortfall generates inefficientpatterns of soil conservation adoption. Observedadoption patterns reflect risk characteristics of thesoil conservation method, differences in risk exposureamong farms, and differences in farm size.  相似文献   
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