Early Trends in Landcover Change and Forest Fragmentation Due to Shale-Gas Development in Pennsylvania: A Potential Outcome for the Northcentral Appalachians

Worldwide shale-gas development has the potential to cause substantial landscape disturbance. The northeastern U.S., specifically the Allegheny Plateau in Pennsylvania, West Virginia, Ohio, and Kentucky, is experiencing rapid exploration. Using Pennsylvania as a proxy for regional development across the Plateau, we examine land cover change due to shale-gas exploration, with emphasis on forest fragmentation. Pennsylvania’s shale-gas development is greatest on private land, and is dominated by pads with 1–2 wells; less than 10 % of pads have five wells or more. Approximately 45–62 % of pads occur on agricultural land and 38–54 % in forest land (many in core forest on private land). Development of permits granted as of June 3, 2011, would convert at least 644–1072 ha of agricultural land and 536–894 ha of forest land. Agricultural land conversion suggests that drilling is somewhat competing with food production. Accounting for existing pads and development of all permits would result in at least 649 km of new road, which, along with pipelines, would fragment forest cover. The Susquehanna River basin (feeding the Chesapeake Bay), is most developed, with 885 pads (26 % in core forest); permit data suggests the basin will experience continued heavy development. The intensity of core forest disturbance, where many headwater streams occur, suggests that such streams should become a focus of aquatic monitoring. Given the intense development on private lands, we believe a regional strategy is needed to help guide infrastructure development, so that habitat loss, farmland conversion, and the risk to waterways are better managed.     

乌鲁木齐市噪声监测现状、问题及对策

简要介绍了乌鲁木齐市噪声环境监测工作的现状,在主城区选择了具有代表意义的点位,采用"定点监测法"与"普查监测法"进行监测,对影响乌鲁木齐市声环境质量的生活噪声、交通噪声、工业噪声和建筑施工噪声做了定点或连续(24h在线)监测。就存在的问题做了分析探讨,并提出了相应的对策建议,以期为进一步改进乌鲁木齐市噪声监测和管理提供参考。     

Vegetation and outdoor recess time at elementary schools: What are the connections?

Empirical and anecdotal evidence suggests that landscapes with more vegetation have a positive impact on children's focus, attention, and cognitive development. In school, children are able to regain focus, suppress impulses, and pay attention in class longer after exposure to natural settings. Because children spend much of their time in school, the amount and types of vegetation on school grounds may influence their development. Public elementary schools in the Commonwealth of Virginia (N = 988) were surveyed to examine correlations between school ground vegetation and outside recess. The number of trees on school grounds, the size of the school grounds, and the presence of sports fields were modestly correlated with greater outside recess time. These correlations support common sense because sports fields facilitate supervised play and larger school grounds provide space for sports fields and playgrounds and additional opportunities for free play. More trees on school grounds provide a welcoming environment for students and teachers, and encourage outside play. These results may help school personnel design and maintain school grounds that increase outdoor recess time.     

一种新型表面处理剂提高电气设备外绝缘防污闪性能的应用技术研究

本文介绍一种新型的表面处理剂,主要针对运行多年的电气设备外绝缘进行表面处理,提高其表面性能,以提高其防污闪能力。该表面处理剂能够在清洁表面污秽的同时,提高外绝缘表面的防污闪性能。对于瓷或玻璃绝缘子,本研究通过表面处理以提高其憎水性和自清洁能力。对于硅橡胶材料制品(复合绝缘子、防污闪涂层、硅橡胶套管等),特别是憎水性减弱或丧失的硅橡胶制品,本研究通过表面处理以提高其憎水性和自清洁能力,从而提高其防污闪能力。     

Alternative natural gas contract and pricing structures and incentives for the LNG industry

Gas conversion to liquefied gas (LNG) and transport by LNG tankers is one option for meeting expanding gas consumption and for gas traded internationally. This paper examines the impact of the traditional gas contract provisions of indefinite pricing, market out price ceilings, and take-or-pay requirements on the profitability of LNG projects in the context of markets characterized by price and quantity uncertainty. Simulation experiments are used to examine and calibrate the effects of those provisions. The results provide guidance to operators, host countries and purchasers in structuring such contracts. The paper also assesses prospects of future expansion of world LNG capacity.     

Impacts after four years of experimental trampling on alpine/sub-alpine environments in western Tasmania

Experimental trials were undertaken over four years to assess the impact of recreational trampling in undisturbed alpine and sub-alpine vegetation communities in the Western Arthur Range, western Tasmania. Data on 'pad' formation due to human trampling were collected using vegetation cover assessments, biomass estimates and detailed cross-sectional surface profiles. In sub-alpine buttongrass and alpine herbfield, prolonged and sustained damage may occur after 100 passes by walkers. The environmental threshold of the flat alpine herbfield site was breached after 200 passes. Plant morphology was one determinant of resistance and resilience, with upright woody shrubs and tall tussock graminoids most vulnerable to sustained trampling damage. Cushions are susceptible to trampling impacts at 500 passes. Loss of vegetation cover peaks 6-12 months after trampling. Our results show that pads formed with as few as 30-100 passes per annum and tracks form at between 100 and 500 passes per annum. Two years after the cessation of trampling, there is some small recovery in vegetation cover after 30 and 100 passes per annum applied for three years, but no evidence of recovery at the 500 pass treatments. The low trampling threshold and slow recovery rates in western Tasmania suggest that concentrating walkers on a minimal number of sites may be the best management option for these untracked alpine and sub-alpine environments.     

REACH SCALE HYDRAULIC ASSESSMENT OF INSTREAM SALMONID HABITAT RESTORATION1

ABSTRACT: This study investigates the use of a two‐dimensional hydrodynamic model (River2D) for an assessment of the effects of instream large woody debris and rock groyne habitat structures. The bathymetry of a study reach (a side channel of the Chilliwack River located in southwestern British Columbia) was surveyed after the installation of 11 instream restoration structures. A digital elevation model was developed and used with a hydrodynamic model to predict local velocity, depth, scour, and habitat characteristics. The channel was resurveyed after the fall high‐flow season during which a bankfull event occurred. Pre‐flood and post‐flood bathymetry pool distributions were compared. Measured scour was compared to predicted shear and pre‐flood and post‐flood fish habitat indices for coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss) were compared. Two‐dimensional flow model velocity and depth predictions compare favorably to measured field values with mean standard errors of 24 percent and 6 percent, respectively, while areas of predicted high shear coincide with the newly formed pool locations. At high flows, the fish habitat index used (weighted usable area) increased by 150 percent to 210 percent. The application of the hydrodynamic model indicated a net habitat benefit from the restoration activities and provides a means of assessing and optimizing planned works.     

外绝缘用液体硅橡胶的自然老化因素研究

近年来,液体硅橡胶(Liquid Silicone Rubber,LSR)已经在外绝缘领域得到了较为广泛的应用,但是目前对其耐老化性能的研究还不够深入。尤其是在中国南方地区使用时,高温、高湿环境更容易导致液体硅橡胶的老化。在许多地区都观察到了电流、电压互感器的液体硅橡胶绝缘外套的龟裂、老化现象,对设备的安全运行产生了影响。本文设计并实施了在光照、高温、高湿、电晕等老化因素作用下的液体硅橡胶人工老化试验,并对老化试验后的样品进行了硬度、力学性能、憎水性、光泽度以及SEM、FTIR等微观性能试验和分析。认为在光照作用下,高温、高湿环境对液体硅橡胶具有加速老化作用,表现为硬度上升、憎水性下降、光泽度下降,并且在表面出现细微裂纹。     

高校校园整体声环境现状评价方法研究

为了能更精确地对高校校园整体声环境现状进行评价,首先对高校校园进行了功能区划分,然后使用判断矩阵法确定了每个功能区的权重,最后使用通过GB3096-2008中规定的普查监测法测量得到的网格噪声数据具体演示了采用模糊综合评判法对一所大学的声环境现状进行评价的方法。此方法比单纯地把校园全部网格噪声数据进行算术平均运算后得到的值来反映高校校园的声环境现状更符合客观实际。     

Enzyme catalyzed biodiesel production from rubber seed oil containing high free fatty acid

Unrefined rubber seed oil contains high levels of free fatty acids and moisture, which make the conventional chemical catalyzed transesterification unsuitable. The method of enzyme catalyzed transesterification is well suited for biodiesel production from rubber seed oil as the enzymes are insensitive to the free fatty acids. In the present work, rubber seed oil was extracted from preserved rubber seed cake by mechanical means. The extraction process was designed and optimized through 2⁴ full factorial design. Extracted oil was subjected to enzymatic transesterification using four different lipases to identify the best one for the purpose. Transesterification process was optimized by considering three influencing variables for biodiesel production viz. methanol/oil molar ratio, catalyst concentration (% w/v) and solvent content (% v/v). A 2³ full factorial design was applied to design the experiments and optimize the biodiesel production. The interactive effects of the independent variables on biodiesel yield were analyzed and regression models were developed for each set of enzyme reactions. Among the four lipases, Thermomysis Lanugonosus Lipase was found to be the most suitable for the transesterification of rubber seed oil with a biodiesel conversion of 92.83% at a molar ratio of 4% and 5% (w/v) enzyme concentration in solvent free reaction medium.     

我国废旧橡胶综合利用的现状及发展建议

随着我国橡胶资源消耗量的增大和废旧橡胶总量的增多，正确合理地引导扶持废旧橡胶综合利用产业已成为不容忽视的问题。本文介绍了废旧橡胶综合利用的主要途径，分析了我国废旧橡胶的综合利用现状，提出了废旧橡胶综合利用的发展建议。     

Evaluation of a denitrification wall to reduce surface water nitrogen loads

Denitrification walls have significantly reduced nitrogen concentrations in groundwater for at least 15 yr. This has spurred interest in developing methods to efficiently increase capture volume to reduce N loads in larger watersheds. The objective of this study was to maximize treatment volume by locating a wall where a large groundwatershed was funneled toward seepage slope headwaters. Nitrogen concentration and load were measured before and after wall installation in paired treatment and control streams. Beginning 2 d after installation, nitrogen concentration in the treatment stream declined from 6.7 ± 1.2 to 3.9 ± 0.78 mg L and total N loading rate declined by 65% (391 kg yr) with no corresponding decline in the control watershed. This wall, which only comprised 10 to 11% of the edge of field area that contributed to the treatment watershed, treated approximately 60% of the stream discharge, which confirmed the targeted approach. The total load reduction measured in the stream 155 m downstream from the wall (340 kg yr) was higher than that found in another study that measured load reductions in groundwater wells immediately around the wall (228 kg yr). This indicated the possibility of an extended impact on denitrification from carbon exported beyond the wall. This extended impact was inauspiciously confirmed when oxygen levels at the stream headwaters temporarily declined for 50 d. This research indicates that targeting walls adjacent to streams can effectively reduce N loading in receiving waters, although with a potentially short-term impact on water quality.     

EFFECTS OF A DAIRY LOAFING LOT-BUFFER STRIP ON STREAM WATER QUALITY1

ABSTRACT: A loafing or sacrifice lot is an area located outside of the free stall barn, where a dairy herd spends several hours per day. Sacrifice lots are usually denuded of vegetation and have high concentrations of manure and urine that can contribute significant amounts of sediment, nutrients, and pathogens to nearby surface waters. In this study, stream water quality impacted by direct runoff from a sacrifice lot was monitored for a period of 20 months. Ambient stream water quality was monitored by grab sampling upstream and downstream of the sacrifice lot. During runoff events, stream water quality downstream of the sacrifice lot was monitored with an automatic sampler. Laboratory analyses were conducted for total suspended solids and nutrients (nitrogen and phosphorus compounds). A grass filter strip (GFS) was installed as a buffer downslope of the sacrifice lot 10 months into the study period. The impact of the buffer strip on the standardized pollutant concentrations and loads was evaluated using the non-parametric Wilcoxon test. The Wilcoxon test indicated that there was no significant difference (α= 0.05) in the standardized yield of sediment and dissolved pollutants before and after the GFS installation, except for phosphate-phosphorus and filtered total phosphorus concentrations, and sediment-bound total phosphorus and total kjeldahl nitrogen loads that decreased significantly. However, load decrease could have been partially caused by the smaller rainfall volumes after the GFS installation as compared to the existing condition.     

WATER USE REDUCTIONS FROM RETROFIHNG INDOOR WATER FIXTURES1

ABSTRACT: A water use model was developed to estimate water savings from installation of low-flow showerheads and toilet displacement devices in residential housing. The model measures household water use in per capita terms with adjustments for age of occupants, household income, if occupants responsible for direct payment of water bill, and type of water fixtures. Detailed data on 308 single family residences involved with a pilot retrofit program in the Seattle, Washington, area were analyzed. We estimated per capita indoor water use to decline by 6.4 and 2.1 percent from complete installation of low-flow showerheads and toilet displacement devices, respectively.     

纳氏试剂光度法测定废水中氨氮的问题讨论

应用纳氏试剂比色法测定废水中的氨氮时,水样显色后稳定时间短,影响测定结果的准确性,针对这一问题进行了实验研究。实验中对主要影响因素Ｉ－和ＯＨ－的浓度变化进行了条件实验,结果表明选用所配的Ⅲ型纳氏试剂（ＫＩ含量为７．５ｇ）,可获得稳定的有色胶体,也可采用Ⅰ型纳氏试剂（ＫＩ含量为７．０ｇ）、在中和硼酸后再多加２ｍＬＮａＯＨ（１ｍｏｌ／Ｌ）,也可获得稳定的有色胶体。     

青藏铁路用空气弹簧橡胶胶料耐紫外线老化试验研究

我国正在建设的青藏铁路是世界上海拔最高、线路最长的高原铁路.其气候特点对橡胶制品提出了新的技术要求,为适应在该气候条件下的运用需要,进行了针对空气弹簧胶囊用橡胶的耐紫外线老化试验研究工作,试验表明随着紫外线老化时间的增加,其硬度和300%定伸强度均提高,但拉伸强度和扯断伸长率随着紫外线老化时间的增加而降低;通过与胶料的耐臭氧试验和大气老化试验比较,基本可以认为引起空气弹簧胶囊表面龟裂的主要原因是受力状况、臭氧和大气老化的作用,而紫外线对橡胶的表面龟裂影响作用不大,因此,为提高空气弹簧胶囊的耐老化性能,主要考虑降低橡胶的受力,提高耐臭氧和耐大气老化性能.     

Environmental citizens: climate pledger attitudes and micro-generation installation

To date, the phenomenon of climate pledging has been little investigated. This paper describes the results of a questionnaire survey of 201 climate pledgers in Greater Manchester (UK), focusing on attitudes and behaviour relevant to environmental citizenship. In particular, attention is given to attitudes and behaviour related to renewable energy and micro-generation, selectively comparing with national UK data. The survey shows that installation cost and lengthy pay-back times have been major constraints on microgen installation not just for the general population, but also for those with a high degree of environmental commitment. Nonetheless, the microgen installation rate among the climate pledgers as of early 2011, before the introduction of feed-in tariffs, was at least 11 times higher than the national average. Using regression analyses, the best model that could be found for explaining installation of the most popular microgen technology, solar thermal, accounted for 27% of variance. Within this model, environmental commitment was of less importance than having given serious consideration to other microgen options. While this was possibly due to group homogeneity, in general, the results do emphasise the limits to environmental citizenship.     

Effectiveness of BMPS in Reducing Sediment From Unpaved Roads in the Stillwater Creek,Oklahoma Watershed1

Turton, Donald J., Michael D. Smolen, and Elaine Stebler, 2009. Effectiveness of BMPs in Reducing Sediment From Unpaved Roads in the Stillwater Creek, Oklahoma Watershed. Journal of the American Water Resources Association (JAWRA) 45(6):1343‐1351. Abstract: Erosion from rural unpaved roads is thought to be an important source of sediment in sediment‐impaired streams in Oklahoma and other locations. However, no direct measurements of sediment yields from rural unpaved roads were previously available for Oklahoma. Four rural unpaved road segments in the Stillwater Creek Watershed were instrumented in a paired watershed design to measure sediment yields to streams before and after the installation of Best Management Practices (BMPs). One segment of each pair remained under current management to serve as a control. The second segment received BMPs after a 1‐year calibration period. One BMP consisted of widening the ditches, re‐shaping ditches and cutslopes, putting a proper crown on the road surface, and vegetating disturbed areas with grass. The other BMP consisted of creating a proper crown on the road bed, applying a geo‐synthetic fabric to the road bed and surfacing with 127 mm of crusher run gravel containing 12‐15% fines to serve as a binder. Road segment sediment yields for individual storms varied, depending on factors such as rainfall amount and intensity. During the pre‐BMP year, storm sediment yields ranged from 0 to 4.3 Mg on one pair of segments and from 0 to 2.8 Mg on the other. The storm sediment yields and annual yields were in the same order of magnitude as sediment yields from unpaved rural or forest roads reported in other studies. Sediment yields were significantly reduced on both segments by the installation of BMPs, approximately 80% on one segment pair and 20% on the other. The average sediment yield (across the four segments) for the pre‐BMP year was 138 Mg/ha or 120 Mg/km of road. By extrapolating these average yields across the 479 km of unpaved roads in the Stillwater Creek Watershed and comparing it to estimated sediment yields for other land uses obtained from other sources, we conclude that unpaved roads may contribute up to 35% of the total sediment load to Stillwater Creek.     

ANALYSIS OF PUMPING TESTS: SIGNIFICANCE OF WELL DIAMETER,PARTIAL PENETRATION,AND NOISE1

ABSTRACT: The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezometers located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.     

Setting Priorities for Research on Pollution Reduction Functions of Agricultural Buffers

The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it. Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest priority is given for work on the surface runoff filtration function, which is almost universally important to the amount of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation. Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments, may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions where buffer installation can substantially reduce stream pollution in these ways. Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation at local scales.