Development of perfluorocarbon tracer technology for underground leak location

A method has been developed for the atmospheric sampling and analysis of four perfluorocarbon tracer (PFT) compounds simultaneously at the parts per trillion (ppt) level. PFTs were pre-concentrated using adsorbent tube air sampling. Analysis was achieved by thermal desorption (TD) and gas chromatography (GC) with electron capture detection (ECD). Efficient separation of the PFTs from the other sample constituents was achieved by use of a capillary porous layer open tubular (PLOT) GC column without the need to cool the GC oven to sub-ambient temperatures using liquid coolants (M. de Bortoli and E. Pecchio, J. High Resolut. Chromatogr., 1985, 8, 422) or for a catalytic destruction step to remove interferents (T. W. D'Ottavio, R. W. Goodrich and R. N. Dietz, Environ. Sci. Technol., 1986, 20, 100). Results from test field trials with two volatile PFTs that were buried to simulate an underground leaking cable were successful. The PFTs were detected above ground level to pinpoint the leak position. The highest tracer concentrations were detected within 1 m of the simulated leak positions 2 days after tracer burial. The developed technology was applied to an oil leaking high voltage electricity cable. One PFT was added to the cable oil which enabled detection of the oil leak to within 3 m. The reported method has many advantages over currently used leak detection methods and could, in the future, be applied to the detection of underground leaks in a variety of cables and pipes.     

Environmental investment recovery practices and opportunities: Lessons from project RENEWAL

In the Autumn 1994 issue of Total Quality Environmental Management you learned about Project RENEWAL, a cooperative business project to investigate and promote the linkages between ecology, technology, and business economics. Project RENEWAL stands for Resource Efficiency Network to Eliminate Waste and Liability. This collaborative effort focused on equipment and inventory assets, exploring how better capital asset management can benefit profitability and improve environmental protection. Participants in the project included representatives from industry, consulting, local and state government, environmental agencies, trade groups, and academia. This article describes three specific activities conducted by the RENEWAL participants and suggests ways to improve the success of future projects looking to improve the investment recovery of “impaired” capital assets.     

Use of agricultural land evaluation and site assessment in Linn County,Oregon, USA

Oregon state law requires each county in the state to identify agricultural land and enact policies and regulations to protect agricultural land use. State guidelines encourage the preservation of large parcels of agricultural land and discourage partitioning of agricultural land and construction of nonfarm dwellings in agricultural areas. A land evaluation and site assessment (LESA) system was developed in Linn County to aid in the identification of agricultural land and provide assistance to decision makers concerning the relative merits of requests to partition existing parcels of ricultural land and introduce nonagricultural uses.Land evaluation was determined by calculating soil potential ratings for each agricultural soil in the county based on the soil potentials for winter wheat, annual ryegrass, permanent pasture, and irrigated sweet corn. Soil potential ratings were expressed on a scale of 0 to 150 points. The land evaluation score for a parcel consists of the weighted average soil potential rating for all of the soils in the parcel, weighted by the percentage of each soil present in the parcel.Site assessment was based on the size of a parcel and on the amount of existing conflict between agricultural and nonagricultural uses, particularly rural residential uses, both adjacent to and in the vicinity of a parcel. Parcel size refers to both size in relation to a typical field and size in relation to a typical farm unit. Conflict takes into account the number of nonfarm dwellings within 1/4 mile (0.4 km) of a parcel, the amount of the perimeter that adjoins conflicting land uses, and the residential density adjacent to the parcel. Empirical scales were derived for assigning points to each of the site assessment factors. Both parcel size and conflict were worth 75 points in the model. For parcel size, 45 points were allocated to field size and 30 points to farm-unit size. For conflict, 30 points were allocated to nonfarm dwellings within 1/4 mile and 45 points to perimeter conflicts.The LESA model was validated by testing on 23 parcels in Linn County for which requests to partition and/or convert to nonagricultural uses had been received by the County Planning Department. This testing was an essential part of the development process, as it pointed out inconsistencies and errors in the model and allowed continuous adjustment of factors and point scales. The results of application of the final model to three of the case studies are presented to illustrate the concepts.Three possible uses of the information generated by the LESA system include determining the relative agricultural value of a parcel, determining grades of agricultural land suitability, and determining the impacts of changing land use on other parcels in the vicinity. Relative agricultural value is a direct outcome of application of the evaluation criteria in the LESA model. Good, marginal, and nonagricultural grades of agricultural suitability were determined by examining the data from all 23 test cases and establishing threshold point values for soil quality, conflict, parcel size, and total LESA score. Impact analyses were not done in this study, but could be achieved by calculating LESA scores for all parcels possibly affected by a land-use change both before and after a proposed change. All three applications fall short of making a specific land-use decision, but they do provide information that should be of value to the local jurisdiction charged with making such decisions.     

Relationship of work-family conflict,gender, and alcohol expectancies to alcohol use/abuse

Numerous studies have documented a positive relationship between work-family conflict and both psychological distress and somatic symptoms. Little research, however, has explored the relationship of work-family conflict to alcohol use/abuse. Consequently, this study investigated the relationship of work-family conflict to several indicators of abusive alcohol consumption. In addition, the moderating influence of gender and tension-reduction expectancies was examined. Data were obtained through household interviews with a random sample of 473 employed adults. As hypothesized, work-family conflict was positively related to abusive alcohol consumption. In addition, there was strong support for the moderating influence of tension-reduction expectancies. As anticipated, the positive relationship between work-family conflict and abusive alcohol consumption was found almost exclusively among individuals who believe that alcohol use promotes relaxation and tension reduction. In contrast, the hypothesis that gender moderates the relationship between work-family conflict and alcohol use/abuse was not supported. Implications for future research and intervention efforts aimed at reducing alcohol abuse in the workforce are discussed.     

A NONTRADITIONAL METHODOLOGY FOR FLOOD STAGE-DAMAGE CALCULATIONS1

ABSTRACT: This paper presents a new methodology to calculate economic losses from hypothetical, extreme flood events, such as the Probable Maximum Flood. The methodology uses economic data compiled from already-available secondary sources, such as U.S. Census data on magnetic tapes, utilizing microcomputer and other electronic media. Estimates of land elevations are obtained from topographic maps, and flood elevations axe estimated using, for example, a dam breach and flood routing (DAMBRK) model (Fread, 1984). The calculations are performed at a disaggregate spatial scale, by various land use and industrial classification categories. The basic areal units are city blocks (for urbanized areas), enumeration districts, and Census tracts. Depth-damage functions, which provide an estimate of damages as a proportion of the existing value of the structure, are estimated statistically. Computer software (called DAMAGE) is used to combine the economic, flood elevation, and depth-damage information to compute economic losses for different possible flood stages and for different inflow events. Two case studies are presented as illustrations of the method.     

Analysis of a summertime PM2.5 and haze episode in the mid-Atlantic region

Observations of the mass and chemical composition of particles less than 2.5 microm in aerodynamic diameter (PM2.5), light extinction, and meteorology in the urban Baltimore-Washington corridor during July 1999 and July 2000 are presented and analyzed to study summertime haze formation in the mid-Atlantic region. The mass fraction of ammoniated sulfate (SO4(2-)) and carbonaceous material in PM2.5 were each approximately 50% for cleaner air (PM2.5< 10 microg/m3) but changed to approximately 60% and approximately 20%, respectively, for more polluted air (PM2.5>30 microg/m3). This signifies the role of SO4(2-) in haze formation. Comparisons of data from this study with the Interagency Monitoring of Protected Visual Environments network suggest that SO4(2-) is more regional than carbonaceous material and originates in part from upwind source regions. The light extinction coefficient is well correlated to PM2.5 mass plus water associated with inorganic salt, leading to a mass extinction efficiency of 7.6 +/- 1.7 m2/g for hydrated aerosol. The most serious haze episode occurring between July 15 and 19, 1999, was characterized by westerly transport and recirculation slowing removal of pollutants. At the peak of this episode, 1-hr PM2.5 concentration reached approximately 45 microg/m3, visual range dropped to approximately 5 km, and aerosol water likely contributed to approximately 40% of the light extinction coefficient.     

Kin discrimination in the spotted hyena (<Emphasis Type="Italic">Crocuta crocuta</Emphasis>): nepotism among siblings

We examined patterns of affiliation, association, and aggression to inquire whether spotted hyenas (Crocuta crocuta) can distinguish among various groups of maternal and paternal siblings. If so, and if these animals conform to predictions of kin selection theory, then behavioral interactions among hyenas should vary with relatedness. We also considered familiarity-based recognition and phenotype matching as mechanisms hyenas might use to recognize kin. Patterns of affiliative behavior indicated that hyenas favored full-sibling littermates over half-sibling littermates or any other group of half-siblings. Rates of dyadic aggression generally did not vary with kinship. Hyenas associated more closely with half-sibling littermates than with non-littermate half-siblings, and hyenas affiliated more with maternal half-siblings than with paternal half-siblings, suggesting that familiarity-based cues might mediate discrimination among these sibling classes. In addition, operation of a phenotype-matching mechanism was suggested by the preference hyenas demonstrated during affiliative interactions for full- over half-sibling littermates, and by their lack of preference in these interactions for half-sibling littermates over non-littermate half-siblings. Phenotype matching was also suggested by our observation that paternal half-siblings cooperated more, and fought less, than did non-kin. Our data indicate that hyenas can discriminate among various types of siblings, that their social behavior conforms to predictions of kin selection theory, and that they recognize kin using mechanisms of both familiarity and phenotype matching.Communicated by S. Alberts