United States Seen 2.54 Centimeter-ing Its Way to Metric System

On May 3, 1971, the Engineers Joint Council sponsored a panel on metrication at its offices in New York City. Bryce MacDonald of EJC was chairman; he had been instructed to invite representatives of various societies. Its purpose was to “present to the Board of EJC a summation of the situation regarding plans for conversion to the metric system.” The EJC Board will later come to a decision whether it will assume a more active role.

George Arnold of Southern Illinois University, Edwardsville, was named to represent the Air Pollution Control Association on the panel because of his long-standing membership in the Metric Association and his efforts toward exclusive use of international units for pollution measurement.

Twenty-two societies were represented. These included ASME, ASTM, SNAME, ASQC, ASHRAE, ISA, ASEE, ASCE, and ESNE. Among those present was Gregory Schultz of the Material Management Society, who is prominent with the American National Standards Institute and the International Standards Organization. Of the societies present, only six have a firm policy in favor of the metric system. The others are cautiously in favor, or using dual units, or waiting to see what Congress will do about the 1971 Department of Commerce Metric Study Report.     

Residential and biological exposure assessment of chemicals from a wood treatment plant

This paper evaluates the results of contamination of residents and residential homes located in close proximity to a Wood Treatment Plant. The plant has produced treated wood products continuously since 1904. The principle chemicals used to treat the wood, which is primarily used for railroad ties (oblong objects laid perpendicular to the rails to act as a base for the tracks), are creosote and pentachlorophenol. For a number of years, the plant burned treated waste wood products containing creosote and pentachlorophenol. First the plant pressure impregnates the wood with creosote and pentachlorophenol, and then the wood is stacked on open ground to allow it to air dry. Chemicals from recently treated wood ties are allowed to evaporate into the air or drip onto the ground surrounding the stacked wood. Small drainage ditches carry the liquid wastes into larger water channels where eventually the waste streams are discharged into a river adjacent to the plant. The river serves as a source of drinking water for the nearby community. Prevailing wind patterns favor a drift of air emissions from the plant's boiler stack over the nearby community and its residents. Over the past few years, the town's residents have become increasingly concerned about their health status and have voiced concerns regarding multiple health problems (including cancer), possibly associated with plant discharges. The intention of this study is to examine a representative sample of the potentially affected residents and to evaluate their residential environment for the presence of dioxin and/or its congeners. Data obtained from EPA's Toxic Release Information (TRI) database revealed the plant routinely discharged creosote, pentachlorophenol, dioxin and dioxin-like compounds into the ambient air via fugitive air emissions and surface waste waters. Sampling of household dust and water sediment within and outside of residences within a 2-mile radius of the plant revealed the presence of significantly elevated levels of dioxins, principally octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,6,7,8-hepta-CDD. Biomonitoring of 29 subjects identified the presence of significantly elevated chlorinated dioxins and furan levels (OCDD=1049 ppt for exposed and 374 ppt for controls and 1,2,3,4,6,7,8-hepta CDD=132 ppt for exposed and 45.1 ppt for controls). These levels are consistent with exposures to pentachlorophenol in this group of subjects. And they confirm the presence of unsafe levels of chlorinated dioxins in these persons.     

PAH-concentrations and compositions in the top 2 cm of forest soils along a 120 km long transect through agricultural areas, forests and the city of Oslo, Norway

The top 2 cm of forest soils were collected along a 120 km long south-north transect running through Norway's largest city Oslo. Forty samples were analysed for their polycyclic aromatic hydrocarbon (PAH(16) as defined by the U.S. Environmental Protection Agency) concentrations and compositions. Local variations in the PAH values are high and the reported concentrations are in general low (maximum sumPAH16: 2.6 mg/kg). The transect shows distinct differences of sumPAH16 values from south to north. PAH concentrations are substantially lower in the less populated areas at the north end of the transect than at the urbanised and much more populated south end. Several high values occur in a forested area to the north of Oslo, used for recreation purposes. The PAH distribution patterns point towards a predominantly pyrogenic origin. Local Cambrian carbon-rich black shales can be excluded as sources for PAHs in the forest soils.     

A Cu tolerant population of the earthworm Dendrodrilus rubidus (Savigny, 1862) at Coniston Copper Mines, Cumbria, UK

Dendrodrilus rubidus were sampled from a mine spoil soil at Coniston Copper Mine, an abandoned Cu mine in Cumbria, UK and a Cu-free control site. Earthworms were maintained for 14d in both Kettering loam and a Moorland soil amended with Cu nitrate. Mortality, condition index, weight change and tissue concentration were determined. In both soils D. rubidus native to the mine site were able to tolerate significantly higher soil Cu concentrations (MWRT, p相似文献   

Performance of wastewater subsurface drip emitters at low and normal pressure.

Subsurface drip distribution is an important on-site wastewater treatment technique widely used with various soil types and restricted site conditions. This study evaluated the performance of five subsurface wastewater drip products under eight pressures, ranging from 0 to 310 kPa. Results showed that Netafim Bioline pressure-compensating emitters (Netafim Irrigation Inc., Fresno, California) had an application uniformity coefficient of 95% and a coefficient of variance (C(v)) of 4.9%. The average uniformity coefficient of Geoflow Wasteflow products (Geoflow USA, Charlotte, North Carolina) was 94.4%, with a C(v) value of 6.8%. Flowrate and pressure relationships were developed by analyzing low and normal operational pressure ranges, and R-square values ranged from 1.000 to 0.301. Geoflow pressure-compensating products were non-pressure-compensating emitters under low pressure. Netafim pressure-compensating emitters were partially pressure-compensating under low pressures. In normal operational pressure ranges, both Geoflow and Netafim products were fully pressure-compensating. Netafim pressure-compensating products were characterized as pressure-compensating over the full range of operational pressures.     

Revisiting Kappa to account for change in the accuracy assessment of land-use change models

Land-use change models are typically calibrated to reproduce known historic changes. Calibration results can then be assessed by comparing two datasets: the simulated land-use map and the actual land-use map at the same time. A common method for this is the Kappa statistic, which expresses the agreement between two categorical datasets corrected for the expected agreement. This expected agreement is based on a stochastic model of random allocation given the distribution of class sizes. However, when a model starts from an initial land-use map and makes changes to it, that stochastic model does not pose a meaningful reference level. This paper introduces K_Simulation, a statistic that is identical in form to the Kappa statistic but instead applies a more appropriate stochastic model of random allocation of class transitions relative to the initial map. The new method is illustrated on a simple example and then the results of the Kappa statistic and K_Simulation are compared using the results of a land-use model. It is found that only K_Simulation truly tests models in their capacity to explain land-use changes over time, and unlike Kappa it does not inflate results for simulations where little change takes place over time.     

Individual specific contact calls of pallid bats (<Emphasis Type="Italic">Antrozous pallidus</Emphasis>) attract conspecifics at roosting sites

Contact calls are utilized by several bird and mammal species to maintain group cohesion and coordinate group movement. From a signal design perspective, contact calls typically exhibit acoustic features that make them easily localizable and encode information about individual or group identity. Pallid bats (Antrozous pallidus) are unusual among vespertilionids in that they often emit a loud, partially audible frequency-modulated social call several times in rapid succession while in flight. This call appears to function as a contact call in that it is frequently given when bats return from foraging and perform circular flights before entering a crevice roost. However, the degree to which pallid bats respond to the calls of conspecifics and what information is provided in the call is unknown. Thus, the goal of this study was to investigate pallid bat calling behavior to determine if calls attract roostmates or elicit responses from them and provide sufficient information for individual recognition. In playback studies, we found that contact calls, elicit calls, and approaches and that free-flying bats respond more to familiar than unfamiliar calls. In addition, analysis of frequency and temporal measurements of calls collected from multiple sites and spectral cross correlation analysis of calls recorded from the same radio-tagged bats on multiple evenings revealed that the frequency pattern of contact calls is highly repeatable over time within individuals but exhibits significant differences among individuals. Thus, contact call structure appears to be unique to individuals and stable through time, which makes these calls well-suited for roostmate recognition.     

用槐叶苹象甲对塞内加尔河水面的槐叶苹进行有效生物控制

1999年,在毛里塔尼亚和塞内加尔的塞内加尔三角洲下部,槐叶苹(Salvinia moesta)的侵入对当地居民的社会经济状况以及湿地生物多样性构成严重的威胁.分别于2000年5月在塞内加尔和毛里塔尼亚及2001年4月在塞内加尔的河面引进槐叶苹象甲(Cyteobagous salviniae),最终实现了对槐叶苹的有效生物控制.2001年10月,象甲起到的作用已非常明显.植物的颜色由绿色变为深褐色或黑色,槐叶苹最终沉入水底.2001年11～12月对槐叶苹象甲扩散的监控证实了生物控制结果的真实性.至2002年4月已有结论,塞内加尔河畔槐叶苹不再成为问题.     

Damage costs of nitrogen fertilizer in Europe and their internalization

This paper estimates the environmental impacts and damage costs (‘external costs’) of synthetic nitrogen fertilizer and discusses options for reducing these impacts, including their consequences for farmers and for producers of fertilizer. The damage costs of the fertilizer life cycle that could be estimated are large, about 0.3 [euro]/kg_N (compared to the current market price of about 0.5 [euro]/kg_N); much of that is due to global warming by N₂O and CO₂ emissions during fertilizer production and N₂O emissions from fertilized fields. Policy options for internalizing these costs are discussed, and the consequences of reduced fertilizer input on crop yield are explored. If the damage costs were internalized by a pollution tax or tradable permits that are auctioned by the government, the economic consequences would be heavy, with a large revenue loss for farmers. However, if it is internalized by tradable permits that are given out free, the revenue loss for farmers is small. The loss for fertilizer producers increases linearly with the amount of external cost that is internalized, by contrast to the loss for farmers which increases quadratically but is very small for a damage cost of 0.3 [euro]/kg_N. Expressed as a change in the fertilizer-dependent part of the farmers' revenue (crop yield × crop price – fertilizer used× fertilizer price), the decrease is less than 0.5% for most crops; the losses are larger only for crops with low [euro]/ha revenue. Averaged over wheat, barley, potatoes, sugar beet and rapeseed, the loss to farmers is about 0.1% in the UK and 0.4% in Sweden. The revenue loss for fertilizer producers is larger, about 8% in the UK and 14% in Sweden.