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1.
Jaimee Lederman 《Journal of the American Planning Association. American Planning Association》2016,82(4):350-362
Problem, research strategy, and findings: Regional conservation initiatives struggle to meet funding needs when complying with the Endangered Species Act (ESA) of 1996 and need money early to pay for required planning and to acquire land to mitigate the impact of development. Transportation agencies struggle to comply with the ESA and have increasingly been willing to fund regional habitat conservation plans (RHCPs) to do so. We review documents from 22 RHCPs and interview representatives of 16 RHCPs to understand how transportation agencies have contributed to funding RHCPs. We find that transportation agencies mitigate their impacts and provide early and consistent financing to facilitate the planning process, help RHCPs establish initial conservation preserves, and allow RHCPs to capitalize on lower land prices during downturns in the development market. We only sample RHCPs in a few states, however, and these examples may not comply with laws in others. Many of the cases studied are recent; time is needed to assess their long-term success. We recommend further study to assess applications to sectors beyond transportation and beyond the areas we studied.
Takeaway for practice: Transportation agencies have struggled to meet environmental requirements and habitat conservation agencies have typically considered transportation agencies threats to the environment. Where adversarial relationships can be overcome, partnerships between transportation and conservation programs can effectively finance habitat conservation while facilitating capital investments in transportation systems. 相似文献
2.
Multipopulation model of membrane-aerated biofilms 总被引:7,自引:0,他引:7
Biofilms cultivated on oxygen-filled gas-permeable membranes grow differently than conventional biofilms, as the chemical species required for growth diffuse from different sides of the biofilm. Oxygen is delivered directly to the base of the biofilm by the membrane, while organic substrates and other soluble nutrients are provided to the upper surface of the biofilm via the water in which the membranes are immersed. This counterdiffusion of nutrients results in a growth environment very different from that of conventional biofilms that receive both oxygen and other nutrients from the water. In recent years, membrane-supported biofilms have been shown to simultaneously remove chemical oxygen demand (COD) and inorganic nitrogen from wastewater in laboratory studies. Several investigators have developed computer models of these biofilms, but they have all focused on a single population of aerobic bacteria. While these models are useful in characterizing the behavior of these biofilms in pure cultures, they are not useful in modeling the behavior of the biofilms in mixed cultures such as those found in wastewater treatment. In this study, a multipopulation biofilm model was developed that includes aerobic heterotrophs, nitrifiers, denitrifiers, and acetoclastic methanogens. The model was constructed with Aquasim software and can predict the COD and inorganic nitrogen removal behavior observed previously in experimental studies. In this paper we present examples of predicted biofilm behavior and compare the results of this multiple-population model with the single-population models published previously. In addition, the behavior of the biofilm is discussed in terms of application to wastewater treatment. 相似文献
3.
Emissions from indoor biomass burning are a major public health concern in developing areas of the world. Less is known about indoor air quality, particularly airborne endotoxin, in homes burning biomass fuel in residential wood stoves in higher income countries. A filter‐based sampler was used to evaluate wintertime indoor coarse particulate matter (PM10‐2.5) and airborne endotoxin (EU/m3, EU/mg) concentrations in 50 homes using wood stoves as their primary source of heat in western Montana. We investigated number of residents, number of pets, dampness (humidity), and frequency of wood stove usage as potential predictors of indoor airborne endotoxin concentrations. Two 48‐h sampling events per home revealed a mean winter PM10‐2.5 concentration (± s.d.) of 12.9 (± 8.6) μg/m3, while PM2.5 concentrations averaged 32.3 (± 32.6) μg/m3. Endotoxin concentrations measured from PM10‐2.5 filter samples were 9.2 (± 12.4) EU/m3 and 1010 (± 1524) EU/mg. PM10‐2.5 and PM2.5 were significantly correlated in wood stove homes (r = 0.36, P < 0.05). The presence of pets in the homes was associated with PM10‐2.5 but not with endotoxin concentrations. Importantly, none of the other measured home characteristics was a strong predictor of airborne endotoxin, including frequency of residential wood stove usage. 相似文献
4.
Physicochemical changes of ω − 3-enhanced farmed rainbow trout (Oncorhynchus mykiss) fillets developed by dietary modification with flaxseed oil and α-tocopheryl acetate (α-TA) were determined during storage at 2 °C. Trout were fed experimental diets for 120 days followed by processing to obtain boneless skinless fillets. The dietary modification increased concentration of total ω − 3 fatty acids in the fillets, which enhanced chances for lipid oxidation during storage. The fillets were vacuum or non-vacuum packed and stored at 2 °C for 10 or 12 days. Dietary α-TA resulted in higher (P < 0.05) concentration of α-tocopherol in fillets during storage; however, it did not retard (P > 0.05) lipid oxidation. Vacuum packaging resulted in much lower (P < 0.05) TBARS and higher (P < 0.05) retention of α-tocopherol during storage than non-vacuum packaging. However, α-tocopherol unlike vacuum packaging better protected ω − 3 FA in the fillets during storage. 相似文献
5.
Mohammed Mahmoud Yuqiong Liu Holly Hartmann Steven Stewart Thorsten Wagener Darius Semmens Robert Stewart Hoshin Gupta Damian Dominguez Francina Dominguez David Hulse Rebecca Letcher Brenda Rashleigh Court Smith Roger Street Jenifer Ticehurst Mark Twery Hedwig van Delden Ruth Waldick Denis White Larry Winter 《Environmental Modelling & Software》2009,24(7):798-808
Scenarios are possible future states of the world that represent alternative plausible conditions under different assumptions. Often, scenarios are developed in a context relevant to stakeholders involved in their applications since the evaluation of scenario outcomes and implications can enhance decision-making activities. This paper reviews the state-of-the-art of scenario development and proposes a formal approach to scenario development in environmental decision-making. The discussion of current issues in scenario studies includes advantages and obstacles in utilizing a formal scenario development framework, and the different forms of uncertainty inherent in scenario development, as well as how they should be treated. An appendix for common scenario terminology has been attached for clarity. Major recommendations for future research in this area include proper consideration of uncertainty in scenario studies in particular in relation to stakeholder relevant information, construction of scenarios that are more diverse in nature, and sharing of information and resources among the scenario development research community. 相似文献
6.
7.
Ethan S. Walker Curtis W. Noonan Erin O. Semmens Desirae Ware Paul Smith Bert B. Boyer Esther Erdei Scarlett E. Hopkins Johnnye Lewis Annie Belcourt Tony J. Ward 《Indoor air》2021,31(4):1109-1124
Household heating using wood stoves is common practice in many rural areas of the United States (US) and can lead to elevated concentrations of indoor fine particulate matter (PM2.5). We collected 6-day measures of indoor PM2.5 during the winter and evaluated household and stove-use characteristics in homes at three rural and diverse study sites. The median indoor PM2.5 concentration across all homes was 19 µg/m3, with higher concentrations in Alaska (median = 30, minimum = 4, maximum = 200, n = 10) and Navajo Nation homes (median = 29, minimum = 3, maximum = 105, n = 23) compared with Montana homes (median = 16, minimum = 2, maximum = 139, n = 59). Households that had not cleaned the chimney within the past year had 65% higher geometric mean PM2.5 compared to those with chimney cleaned within 6 months (95% confidence interval [CI]: −1, 170). Based on a novel wood stove grading method, homes with low-quality and medium-quality stoves had substantially higher PM2.5 compared to homes with higher-quality stoves (186% higher [95% CI: 32, 519] and 161% higher; [95% CI:27, 434], respectively). Our findings highlight the need for, and complex nature of, regionally appropriate interventions to reduce indoor air pollution in rural wood-burning regions. Higher-quality stoves and behavioral practices such as regular chimney cleaning may help improve indoor air quality in such homes. 相似文献
8.
The introduction and use of formal (mathematically based) specification in substantial systems development has been hampered by the additional burdens it places on practitioners. BT and Leeds Metropolitan University have developed a framework for the gradual introduction of formal specification starting with its use as a review technique, applied to a standard range of systems development deliverables such as data and process models. The benefits of this approach are immediate and can also be more extensive. The paper describes the philosophy behind the general approach, offers an example of applying the Rigorous Review Technique, and summarises the benefits that can accrue 相似文献
9.
B. Semmens A. B. Meggy 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1966,16(4):125-128
The dissolution of kaolinite in aqueous solutions of hydrofluoric acid was investigated at different temperatures and fluoride concentrations. The percentage dissolution of kaolinite was greater than was to be expected from a theoretical consideration of the reaction. The percentage dissolution was less for Na-kaolinite than for a H-kaolinite under the same experimental conditions. Two reaction rates were observed. The relative intensities of the 001 and 002 basal reflections decreased with reaction time, temperature and hydrofluoric acid concentration. The decrease was probably due to an amorphous phase. Although kaolinite samples after treatment at the lower temperature showed very little change in their infra-red absorption spectra, a marked change in the spectra was observed at the higher temperature. The disruption of the kaolinite crystal lattice is believed to be due to the preferential extraction of aluminium from the lattice leaving an intermediate silica phase, which dissolves to form fluorosilicic acid. 相似文献
10.
This study was undertaken specifically to collect engineering and process performance information on the behaviour of a membrane supported bio-film in a well-characterised bioreactor. A novel membrane aerated bioreactor has been tested in the laboratory on synthetic sewage, and also piloted for the treatment of primary effluent at a local municipal wastewater treatment plant. The reactor's design employs gas-permeable, hollow-fibre membranes that are submerged in the wastewater. Air is blown through the inside of the fibres. Aeration costs for such a reactor are likely to be lower than conventional systems because gas compression is not required. Thick bio-films grow on the outside of the fibres and effectively treat the wastewater. The bio-films grown in this manner are capable of biological oxygen demand (BOD) removal, nitrification, denitrification, and simultaneous sludge digestion. The character of the bio-film is very different from conventional bio-films grown on inert surfaces, since in this case the bio-film receives its oxygen and the wastewater components from different directions. In pilot studies, a reactor having a hydraulic residence time of 6.5 h and equipped with no sedimentation tank achieved 70–75% BOD and nitrogen removal, and produced an effluent containing less than 30 mg/l total suspended solids. 相似文献