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641.
Patrick Alexander Ray Mehmet Ümit Taner Katherine Elizabeth Schlef Sungwook Wi Hassaan Furqan Khan Sarah St George Freeman Casey Matthew Brown 《Journal of the American Water Resources Association》2019,55(4):920-937
There has recently been a return in climate change risk management practice to bottom‐up, robustness‐based planning paradigms introduced 40 years ago. The World Bank's decision tree framework (DTF) for “confronting climate uncertainty” is one incarnation of those paradigms. In order to better represent the state of the art in climate change risk assessment and evaluation techniques, this paper proposes: (1) an update to the DTF, replacing its “climate change stress test” with a multidimensional stress test; and (2) the addition of a Bayesian network framework that represents joint probabilistic behavior of uncertain parameters as sensitivity factors to aid in the weighting of scenarios of concern (the combination of conditions under which a water system fails to meet its performance targets). Using the updated DTF, water system planners and project managers would be better able to understand the relative magnitudes of the varied risks they face, and target investments in adaptation measures to best reduce their vulnerabilities to change. Next steps for the DTF include enhancements in: modeling of extreme event risks; coupling of human‐hydrologic systems; integration of surface water and groundwater systems; the generation of tradeoffs between economic, social, and ecological factors; incorporation of water quality considerations; and interactive data visualization. 相似文献
642.
The October 2005 earthquake in northern Pakistan severely affected the livelihoods of 1.5 million people. With the destruction of material assets and communications infrastructure, the quake had a devastating impact on people's way of life in this remote mountainous region. This paper explores livelihood revival interventions undertaken during the earthquake response, and considers how differentiated livelihood outcomes were achieved. In addressing this objective the paper examines livelihood rehabilitation schemes in terms of structural aspects, working strategies, key factors, strengths of interventions and the role of human agency in influencing livelihood trajectories of quake‐affected communities. Primary data for this study was gathered in northern Pakistan between October 2008 and January 2009. The study identifies structural shortcomings and strengths of the programmes attempting to revive the livelihoods of poor and vulnerable households. It identifies how households in two villages made the most of opportunities to improve their lives and move towards favourable outcomes. 相似文献
643.
Sludge granulation and e ciency of phase separator in UASB reactor treating
combined industrial e uent 总被引:1,自引:0,他引:1
Abdullah Yasar Nasir Ahm Muhammad Nawaz Chaudhry Aamir Amanat Ali Khan 《环境科学学报(英文版)》2007,19(5):553-558
Sludge granulation and the effect of gas-liquid-solid separator (GLSS) design on the efficiency of upflow anaerobic sludge blanket (UASB) and upflow anaerobic sludge filter (UASF) reactors, operating at HRTs ranging from 3 to 12 h was investigated. VSS/TS ratio gradually increased in both the reactors with increasing sludge age (from 0.5 to more than 0.7 for UASB reactor and 0.012 to 0.043 for UASF reactor). X-Ray diffraction analysis of the UASF sludge showed the presence of expanding clays revealing its additional absorption capability. Fuoraphyllite and albite precipitation related to excellular polymers of the microbial shell structure, showed the extended growth of microorganisms during sludge granulation. A gradual decrease (82%-69%) in COD removal with decreasing HRT was apparent in UASF reactor. In case of UASB reactor, this decrease was marginal because addition of GLSS device significantly improved (14%-20%) the overall efficiency of the UASB reactor. GLSS enhanced the efficiency of the UASB reactor by increasing the settleability of suspended particles and accelerating the coagulation of colloidal particles due to the velocity gradient. 相似文献
644.
Miriam H. Inoue Rubem S. Oliveira Jr Jamil Constantin Diego G. Alonso Cássio A. Tormena 《Journal of environmental science and health. Part. B》2013,48(8):757-763
This research was aimed at understanding the dynamics of the herbicides diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea], imazapic [2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)-5-methylnicotinic acid] and isoxaflutole [5-cyclopropyl-4-(2-methanesulfonyl-4-trifluoromethyl benzoyl)isoxazole] in two soils of different physico-chemical properties. To accomplish such intent, several greenhouse experiments were run. The bioavailability of diuron (0; 1.6 and 3.2 kg ha? 1), imazapic (0; 98 and 122.5 g ha? 1) and isoxaflutole (0; 35 and 70 g ha? 1) was measured in samples from a sandy loam soil and a clay soil, by sowing a bioindicator (Brachiaria decumbens), at 0, 25, 50, 75 and 100 days after herbicides application (DAA). Diuron was very stable in clay soil, providing control equal to or higher than 92% of bioindicator, up to 100 DAA, as assumed by biomass accumulation. No differential effect was observed in sandy loam soil, even when 2x labeled rate were applied. Imazapic provided a short bioavailability in relation to B. decumbens, independent of rates applied. The persistence of isoxaflutole was longer in clay soil (28 to 30 days). 相似文献
645.
Nazia Umar Khan N. P. Bharathi Sheikh Shreaz Athar Adil Hashmi 《Journal of Polymers and the Environment》2011,19(3):607-614
This paper describes an ecofriendly development of a nanodrug delivery vehicle from seed oil. The entire synthesis, starting
from the ZnO nanoparticle to the polymeric vehicle is purely microwave assisted with minimal usage of organic solvents. Multifunctional
features like enhanced UV absorbance, antimicrobial properties and appreciable in vitro release can be attributed to the nanoparticle
loaded polymeric vehicle. Characterization of the synthesized species was done through FT-IR, 1HNMR, SEM and XRD. The physical characterizations were carried out using conventional laboratory techniques. 相似文献
646.
Nusrat Sharmin Ruhul A. Khan Stephane Salmieri Dominic Dussault Monique Lacroix 《Journal of Polymers and the Environment》2012,20(3):698-705
Chitosan was dissolved in 2?% aqueous acetic acid solution and the films were prepared by solution casting. Values of tensile strength (TS), tensile modulus (TM), elongation at break (Eb?%) and water vapor permeability (WVP) of the chitosan films were found to be 30?MPa, 450?MPa, 8?% and 4.7?g?mm/m2?day?kPa, respectively. Poly(caprolactone) (PCL) films were prepared from its granules by compression molding and the values of TS, TM, Eb and WVP were 14?MPa, 220?MPa, 70?% and 1.54?g?mm/m2?day?kPa, respectively. PCL was reinforced with chitosan films, and composite films were prepared by compression molding. Amount of chitosan in the composite films varied from 10 to 50?% (w/w). It was found that with the incorporation of chitosan films in PCL, both the values of TS and TM of composite films increased significantly. The highest mechanical properties were found at 50?% (w/w) of chitosan content. The Oxygen transmission rate (OTR) of composite film was found to decrease significantly than PCL films. Thermal properties of the composite were also improved as compared to PCL. The water uptake test of the composite also showed promising results with a good stability of composite films. The interface of the composite was investigated by scanning electron microscopy and showed good interfacial adhesion between PCL and chitosan films. 相似文献
647.
Mohd Imran Khan Iqbal Ahmad Abbas Ali Mahdi Mohd Javed Akhtar Najmul Islam Mohd Ashquin Thuppil Venkatesh 《Environmental science and pollution research international》2010,17(7):1347-1354
Background, aim, and scope
Lead, a major contaminant, is highly used in paint manufacturing due to its anticorrosive properties. Recent reports indicated high lead content among Indian paints used for commercial purposes. Painters are continuously exposed to these lead containing paints during painting of both commercial as well as residential buildings. Lead is well-known for its genotoxicty in occupational workers; however, in Indian painters the genotoxic effects of lead have not been reported to date. Therefore we aimed to study the genotoxic end points in painters due to their long-term exposure to these high lead-containing Indian paints. 相似文献648.
A simple and efficient ionic liquid-based ligandless microextraction method has been developed for preconcentration of cadmium ions (Cd2+) as a step prior to its determination by flame atomic absorption spectrometry (FAAS) with a micro-sample introduction system. In this approach, the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] and ethanol were used as extractant and dispersive solvents to preconcentrate the Cd2+ in different waters, acid digested scalp hair, and nail samples. Some analytical parameters influencing the extraction efficiency of Cd2+ and its subsequent determination, including pH, IL volume, dispersant solvent volume, sample volume, temperature, incubation time, and matrix effect, were optimized. Under optimal conditions, the limit of detection (LOD), limit of quantification (LOQ), and enhancement factor (EF) were 0.4 μg L?1, 1.3 μg L?1, and 50, respectively. The relative standard deviation (RSD) of 100 μgL?1 Cd2+ was 4.3% (n = 6). The validity of the proposed method was checked by determining Cd2+ in certified reference material (TM-25.3 fortified water) and standard addition; the results showed sufficient recovery (>98%) of Cd2+ within the certified value. The method was applied for preconcentration and determination of cadmium in waters and biological samples. 相似文献
649.
M. Mahboob M.K.J. Siddiqui Kaiser Jamil 《Journal of environmental science and health. Part. B》2013,48(6):739-749
Abstract Subacute oral toxicity of a newly developed phosphorothionate insecticide (2‐butenoic acid‐3‐(diethoxy‐phosphinothioyl) methyl ester), coded as RPR‐2, was studied in male rats by oral (multiple) intubation of low (0.014 mg kg‐1 day‐1), medium (0.028 mg kg‐1 day‐1), and high (0.042 mg kg‐1 day‐1) dose for 90 days. The medium and high dose produced toxic symptoms along‐with some mortality (20%) occurred in the high dose treated rats. The medium and high doses caused significant inhibition in cytochrome P‐450 activity in liver, lung, kidney and brain tissues at 45 and 90 days. The high dose caused significant decrease in cyt.b5 activity of all the four tissues at 45 and 90 days. Whereas, medium dose brought such effect in liver and lung at 45 and 90 days. Kidney and brain cyt.b5 activity decreased significantly at 90th day due to medium dose. Low dose also caused inhibition in cyt.b5 activity in brain at 90th day. Cytochrome P‐450 reductase activity was decreased significantly in liver, lung, kidney and brain at 45 and 90th by the medium and high dose. The results indicated that RPR‐2 had potential to modulate hepatic and extra‐hepatic cyt.P‐450 dependent monooxygenase system of rat due to subacute exposure. These metabolic alterations were quite reversible after 28 days withdrawal of treatment. 相似文献
650.
We examine the frequency of reciprocal exchanges of helping behavior in three red-cockaded woodpecker populations to determine
if such exchanges might constitute a significant fitness benefit of helping. Specifically, we determine how often helpers,
once they become breeders, are assisted by young they previously helped raise. The estimated frequencies of reciprocal exchange
of helping based on survival and status transition probabilities are low (2%). Observed frequencies of reciprocity are significantly
higher than estimated frequencies in two of the three populations studied, suggesting that male fledglings more often remain
on their natal territory as helpers if another helper is already present. High rates of retention of young males as helpers
on high-quality territories or preferential helping of kin, as well as preferential helping of former care-givers, might explain
this result. When the analysis is restricted to helpers unrelated to the young they help raise, which controls for preferential
helping of kin and largely eliminates effects of territory quality, empirical estimates of the frequency of reciprocity do
not differ from estimates calculated from population demography. We conclude that young males do not preferentially help former
care-givers and that reciprocal exchange of help is not an important factor in the evolution of helping behavior in the red-cockaded
woodpecker. In this species, all known benefits of helping behavior are indirect (i.e., derived through kin selection ) rather
than direct. We discuss the occurrence of unrelated helpers in this context.
Received: 10 August 1999 / Received in revised form: 13 February 2000 / Accepted: 19 February 2000 相似文献