Search

Racial/ethnic minority girls have a history of being underrepresented in STEM. Yet, there is a dearth of research that identifies the mathematics experiences that predict being on a STEM pipeline. Analyzing data from the Educational Longitudinal Study (ELS: 2002), we examined the relationship between mathematics attitudes, beliefs, and enrichment activities and being on a STEM pipeline among racial/ethnic minority girls. The findings indicated that for Black and Latinx girls, higher levels of mathematics self-efficacy beliefs were associated with being on a STEM pipeline. For American Indian/Alaska Native girls, endorsing a growth mindset was associated with being on a STEM pipeline. For Asian, Hawaii/Pacific Islander girls, mathematics enjoyment was associated with being on a STEM pipeline. Yet, endorsing higher levels of participation in mathematics enrichment activities and mathematics self-efficacy beliefs was associated with lower endorsements of being on a STEM pipeline for Black and American Indian/Alaska Native girls, respectively. Results build on previous work by highlighting important mathematics experiences that impact being on a STEM pipeline for racial/ethnic minority girls.

Poor air quality in Alaska’s remote communities due to road dust is one of the top environmental concerns of residents in these communities. Most communities are disconnected from the road network, with community roads that are predominantly unpaved. In Alaska, high costs limit widespread paving of roads, leaving communities to rely on alternative dust control strategies. The goals for this study were to assess the magnitude and impact of the dust problem in rural Alaska and use a diversity of experience, including regulatory, research, engineering, and cultural, to develop a road-dust management approach for rural Alaska. The plan incorporates different levels of dust management: institutional controls, road watering, chemical dust suppressants, and road surface stabilization. Geographical zones where use of each different dust management level will be most appropriate are identified based on rainfall frequency. Approximately 50% of Alaska’s communities can manage road dust with institutional controls and road watering. Many of the road-dust management ideas presented are transferable to other global regions that experience similar economic and community access challenges as Alaska.

Intrusion of volatile organic compounds in the gas phase has impacted many buildings in many different locations. Various building and environmental factors such as buoyancy of heated air and changes in barometric pressure can influence indoor air concentrations due to vapor intrusion in these buildings resulting in seasonal and daily variability. One environmental factor that previous research has not adequately addressed is soil temperature. In this study we present two northern region study sites where the seasonal trends in indoor air VOC concentrations positively correlate with soil temperature, and short-term (days) variations are associated with barometric pressure changes. We present simple and multivariate linear relationships of indoor air concentrations as a function of soil temperature and barometric pressure. Results from this study show that small changes in soil temperature can result in relatively large changes in indoor air VOC concentrations where the gas phase VOCs are sourced from non-aqueous phase liquids contained in the soil. We use the results from this study to show that a five degree Celsius increase in soil temperature, a variation in soil temperature that is possible in many climatic regions, results in a two-fold increase in indoor air VOC concentrations. Additionally, analysis provides insight into how building ventilation, diffusion, and the relative rate of soil-gas flow across the slab both from the subsurface into the building and from the building into the subsurface impact short term variations in concentrations. With these results we are able to provide monitoring recommendations for practitioners.

The novel coronavirus SARS-CoV-2, the causative agent of COVID-19, emerged in the human population in December 2019 and spread worldwide within a few short months. Much of the public health focus for preventing and mitigating the spread of COVID-19 has been on individual and collective behaviors, such as social distancing, mask-wearing, and hygiene. It is important to recognize that these behaviors and health outcomes occur within broader social and environmental contexts, and factors within local communities such as regional policy, historical context, cultural beliefs, and natural- and built environmental characteristics affect underlying population health and the spread of disease. For example, the COVID-19 pandemic has renewed attention to the importance of secure water and sanitation services in protecting human health; many remote Alaskan communities are particularly vulnerable to infectious disease transmission because of inadequate water and sanitation services. In addition, there are a number of socio-economic, physical, and infrastructure factors in rural Alaska (e.g., remoteness, household overcrowding, climate change impacts, limited medical facilities, and high prevalence of chronic diseases) that contribute to the potential for more severe COVID-19 disease outcomes in these predominantly Alaska Native communities., Graphical abstract Unlabelled Image

Alternative landfill covers utilizing evapotranspiration (ET) as the primary mechanism for protecting the waste layer from aerial moisture represent promising tools for cold region solid waste management. However, ET covers have not been evaluated for use in subarctic climates. As the functionality of an ET cover is driven primarily by climactic variables, climate-specific field tests are required prior to widespread implementation. The objective of this study was to evaluate the four-year performance of two competing pilot-scale landfill covers built atop drainage lysimeters near Anchorage, AK. The compacted soil cover (CSC) was designed and constructed according to standards prescribed by Alaska solid waste regulations. The alternative ET cover design was based upon a preliminary modeling study. After four years, the two adjacent lysimeters had each received a total of 1636 mm precipitation. Over that period, 201 mm moisture drained from the ET lysimeter, compared to 292 mm in the CSC lysimeter. The difference in drainage rates between the two covers was most apparent during the autumn season, when the drainage rates for both covers were at their annual maximum. The lower autumn and annual drainage rates observed in the ET lysimeter after the first year were potentially due to higher moisture storage capacity in the ET cover soils and/or formation of preferential flow paths in the CSC soils. Analysis of soil temperature, precipitation, and drainage data indicated that negligible amounts of winter precipitation infiltrated the ET cover during winter, and that the frozen soils promoted runoff over drainage during the spring melt. These results indicate that similar ET cover designs merit consideration for broader use in subarctic conditions.

At a site with discontinuous permafrost in Fairbanks, Alaska, releases of trichloroethene (TCE), an industrial solvent, have caused contamination of the groundwater. The objective of this study was to investigate the relationship between the migration pathway of the TCE groundwater plume and the distribution of the discontinuous permafrost at the site. The TCE plume configuration is substantially different than what regional hydrology trends would predict. Using GIS, we conducted a geostatistical analysis of field data collected during soil-boring installations and groundwater monitoring well sampling. With the analysis results, we constructed maps of the permafrost-table elevation (top of permafrost) and of the groundwater gradients and TCE concentrations from multiyear groundwater sampling events. The plume concentrations and groundwater gradients were overlain on the permafrost map to correlate permafrost locations with groundwater movement and the spatial distribution of TCE moving with groundwater. Correlation of the overlay maps revealed converging and diverging groundwater flow in response to the permafrost-table distribution, the absence of groundwater contamination in areas with a high permafrost-table elevation, and channeling of contaminants and water between areas of permafrost. In addition, we measured groundwater elevations in nested wells to quantify vertical gradients affecting TCE migration. At one set of nested wells down gradient from an area of permafrost we measured an upward vertical gradient indicating recharge of groundwater from the subpermafrost region of the aquifer causing dilution of the plume. The study indicates that the variable distribution of the permafrost is affecting the way groundwater and TCE move through the aquifer. Consequently, changes to the permafrost configuration due to thawing would likely affect both groundwater movement and TCE migration, and areas that were contaminant-free may become susceptible to contamination.

The use of triclopyr for the removal of woody and broad-leaf vegetation in right-of-ways and agricultural settings has been proposed for Alaska. Triclopyr concentrations in soil after application are of concern because residual herbicide may affect growth of subsequent vegetation. In order to measure triclopyr residues in soil and determine the amount of herbicide taken up by the plant, soil bioassays were developed. Four agricultural species, turnip, lettuce, mustard, and radish, were tested to determine sensitivity to triclopyr in a 1-wk bioassay. The sensitivity (I50) of turnip, lettuce, mustard, and radish was 0.33 ± 0.05 kg ai ha−1, 0.78 ± 0.11 kg ai ha−1, 0.78 ± 0.07 kg ai ha−1, and 0.85 ± 0.10 kg ai ha−1 (mean ± SE), respectively. Mustard was the most consistent crop in the bioassay with a midrange response to triclopyr and lowest standard deviation for germination as compared to the other species. Thus, it was used in a bioassay to determine triclopyr concentrations in a field trial. The bioassay of mustard closely matched residual amounts of triclopyr in a field trial determined by chemical extraction. Estimates of residual triclopyr concentrations using the bioassay method were sometimes less than the triclopyr concentration determined using a chemical extraction. These differences in concentrations were most evident after spring thaw when the chemical extraction determined there was enough triclopyr in the soil to reduce mustard growth over 60%, yet the bioassay measured only a 10% reduction. The chemical extraction method may have identified nonphototoxic metabolites of triclopyr to be the herbicidal triclopyr acid. These methods, when analyzed together with a dose–response curve, offer a more complete picture of triclopyr residues and the potential for carryover injury to other plant species.

Knowledge of the factors that influence the diffusion of contaminants, such as the diffusivity and the connected porosity, is crucial to modeling the long-term fate and transport of contaminants in subsurface systems with small or negligible advective flow, such as in fractured crystalline rock. Fractured rock is naturally heterogeneous, and hence, understanding the diffusivity of a molecule through this material (or the formation factor of the medium) becomes a complex problem, with critical concerns about the scale of laboratory measurements and about the spatial variability of these measurements relative to the scale needed for fate and transport modeling. This study employed both electrical and tracer-based laboratory methods to investigate the effects of scale and pore system connectivity on the diffusivity for volcanic matrix rock derived from the study site, a former underground nuclear test site at Amchitka Island, Alaska. The results of these investigations indicate a relatively well-connected pore system with scale effects generally limited to approximately 6 cm lengths and well-correlated to observed heterogeneous features. An important conclusion resulting from this study, however, is that there is a potential for the estimated diffusivity to be misrepresented by an order of magnitude if multiple samples or longer sample lengths are not used. Given the relatively large number of measurements resulting from these investigations, an analysis of the probability density function (PDF) of the diffusivity was possible. The PDF of the diffusivity was shown to generally follow a normal distribution for individual geologic layers. However, when all of the geologic layers are considered together, the distribution of the subsurface as a whole was shown to follow a lognormal distribution due to the order of magnitude differences amongst the layers. An understanding of these distributions is essential for future stochastic modeling efforts.

People living without piped water and sewer can be at increased risk for diseases transmitted via the fecal-oral route. One rural Alaskan community that relies on hauling water into homes and sewage from homes was studied to determine the pathways of fecal contamination of drinking water and the human environment so that barriers can be established to protect health. Samples were tested for the fecal indicator, Escherichia coli, and the less specific indicator group, total coliforms. Shoes transported fecal contamination from outside to floor material inside buildings. Contamination in puddles on the road, in conjunction with contamination found on all-terrain vehicle (ATV) tires, supports vehicle traffic as a mechanism for transporting contamination from the dumpsite or other source areas to the rest of the community. The abundance of fecal bacteria transported around the community on shoes and ATV tires suggests that centralized measures for waste disposal as well as shoe removal in buildings could improve sanitation and health in the community.

People living without piped water and sewer can be at increased risk for diseases transmitted by the fecal-oral route. One Alaskan community that relies on hauled water and sewage was studied to determine the pathways of fecal contamination of drinking water and the human environment so that barriers can be established to protect human health. Samples were tested for the fecal indicators Escherichia coli and Enterococcus. Several samples were tested for the pathogens Giardia lamblia and Cryptosporidium parvum and source tracking methods were employed. Surface water flow transported bacteria within the community during spring thaw and human fecal contamination was detected in town, but flow from the dump did not appear to contribute to contamination in town. Within the home, fecal bacteria were found on water dippers, kitchen counters and floors, and in hand-washing basins. Giardia was found at the dump, but not in water from the river adjacent to the community. Exposure to fecal contamination could be red...

Arctic soil samples were experimentally subjected to freeze–thaw cycles (FTC) between + 5 °C and − 5 °C and to stable temperature regimes of + 5 °C and − 5 °C to investigate how the microorganisms' ability to mineralize oil contamination is affected by different temperature regimes. Hydrocarbon mineralization was monitored in oil contaminated soil microcosms spiked with radiolabeled hexadecane and phenanthrene. Both fertilized and unfertilized soils were used. Mineralization of radiolabeled compounds was demonstrated in all treatments. In soils kept stable at − 5 °C hydrocarbon mineralization was low, but detectable for hexadecane and phenanthrene, both in fertilized and unfertilized soil. Greatest mineralization rates were determined in fertilized soil samples kept stable at + 5 °C where up to 54 mg hexadecane/kg/day and 11 mg phenanthrene/kg/day were measured. Mineralization did not come to a complete stop when the temperature was changed to − 5 °C, but was considerably reduced compared to the + 5 °C mineralization rates. FTC stimulated hexadecane mineralization compared to constant temperature. Phenanthrene mineralization, on the other hand, was constrained by FTC. FTC did not seem to affect the microbial populations in the soil in a negative way, and the total number of cultivable microorganisms increased during the experimental period. The freeze–thaw experiments demonstrate that mineralization of both hexadecane and phenanthrene is occurring in soils undergoing seasonal temperature fluctuations, both above and below freezing temperatures.

Understanding the formation of pore ice in coarse grained soils is important to geotechnical and geo-environmental projects such as the construction of roads, airstrips and gravel foundations as well as the treatment of contaminated soils in the arctic, sub-arctic, alpine and northern regions. The amount of pore ice present impacts the strength characteristics of the soils as well as the flow of fluid through soil. Tests have been conducted to qualify the impact of gradation, temperature, compaction and initial moisture content on the formation of pore ice in coarse grained soils. The purpose of this study was to prepare a conceptual model of the freezing mechanism in coarse grained soils and to qualify the parameters that influence the ice formation. Results from this study indicate that the presence of fine particles in a coarse grained soil greatly impact the depth at which the pore space initially becomes saturated with ice. A conceptual model was developed and its application is shown with regards to the process of thaw weakening in roads and the creation of preferential flow paths in permeable reactive barriers.

In today’s increasingly competitive markets, greater emphasis is being placed on customer service as a means of achieving competitive advantage. Many organizations believe that e-business can provide opportunities to improve customer service operations by enabling them to get closer to the customer and enhance the organization-to-customer contact experience. However, use of the Internet fundamentally changes the nature of the customer contact experience. This article investigates this phenomenon from an operations management perspective, by examining the customer service encounter during the business processes of ordering and delivering in e-business. Empirical results from case research investigating eight companies that use e-business in their customer service operations are reported and discussed. The article concludes that unless the emotional aspects of customer service are considered alongside the functional, then barriers to enhanced customer service in e-business will not be overcome.

In this paper, we briefly describe the clean-up and remediation of a major watershed in Kazakhstan, the Nura River, that was impacted by rapid industrial development during the Soviet era, leaving a legacy of mercury pollution impacting hundreds of thousands of people. Fresh waters, including rivers, lakes, glaciers, groundwater, man-made reservoirs and canals represent less than 3 percent of the earth’s water. Watersheds are closely linked ecosystems that are natural units of analysis and management. Over the last century, the use of freshwater systems has grown at an unprecedented rate to supply and support industrial and agricultural production. Remediation of damaged watersheds and sustainable water management are important tools to minimize the impact of the human activities, especially industrial activities, on the ecosystem services provided by a healthy watershed. Based on engineering reports and data, we discuss the importance of adaptive management strategies, flexibility, and place-based Hg remediation criteria, as well as the value of stakeholder input in a polycentric project management approach.

[1] Temporal atmospheric pressure variations introduce an artifact into percolation measurements in free-draining lysimeters. This anomaly is associated with transient pressure gradients that occur as fluid and gas pressures within the lysimeter equilibrate with atmospheric pressure changes at the drain. On the basis of harmonic (Fourier) analysis of a large (20 m × 10 m × 1.8 m) free-draining lysimeter, hourly percolation was maximally affected by pressure variations of ∼2 cycles per day, with the effect decreasing with decreasing frequency. Compared to the calculated pressure differences at the drain, the measured phase delay between percolation and the atmospheric pressure was less by ∼45°, which we attribute to an additional phase lag existing between the percolation and pressure difference at the drain. These pressure-induced changes in percolation rate can influence the outcome of water balances conducted via free-draining lysimeters.

[1] Diffusion coefficients and effective, or transport, porosities are important parameters in the assessment of the fate and transport of contaminants in fractured rock systems and when contaminant transport needs to be considered in zones of low to negligible advective flows. This study presents and discusses various solutions, analytical and semianalytical, to Fick's law for the typical through-diffusion experiment and applies these solutions to the results of three through-diffusion experimental data sets. These through-diffusion experiments were conducted on two natural breccia samples, with bulk measured porosities of approximately 13.7% and 16.8%, and one manufactured porous plate sample with a bulk measured porosity of 40.9%, such that the samples displayed order of magnitude differences in their diffusivities. For each experiment, the derived effective porosities and intrinsic diffusion coefficients for each method are compared. It was shown that the semianalytical solution provides an improved method for reliably estimating the effective porosity from through-diffusion experimental data; however, there is little difference between methods in the derived intrinsic diffusion coefficients.

An international industry-government consortium is developing a fuelcell hybrid switcher locomotive for commercial railway applications and power-to-grid generation applications. The current phase of this on-going project addresses the practicalities of on-board hydrogen storage, fuelcell technology, and hybridity, all with an emphasis on commercially available products. Through practical evaluation using designs from Vehicle Projects’ Fuelcell-Powered Underground Mine Loader Project, the configuration of the fuelcell switcher locomotive changed from using metal-hydride hydrogen storage and a pure fuelcell power plant to using compressed hydrogen storage, a fuelcell-battery hybrid power plant, and fuelcell stack modules from Ballard Power Systems that have been extensively used in the Citaro bus program in Europe. The new overall design will now use a RailPower battery hybrid Green Goat™ as the locomotive platform. Keeping the existing lead-acid batteries, we will replace the 205 kW diesel gen-set with 225 kW of net fuelcell power, remove the diesel fuel tank, and place 14 compressed hydrogen cylinders, capable of storing 70 kg of hydrogen at 350 bar, on the roof. A detailed design with associated CAD models will allow a complete build of the fuelcell-battery hybrid switcher locomotive in the next funded phase.

It is increasingly clear that a wide range of stakeholders should be included in the problem formulation phase of research aimed at solving environmental problems; indeed the inclusion of stakeholders at this stage has been formalized as an integral part of ecological risk assessment. In this paper, we advocate the additional inclusion of stakeholders in the refinement of research methods and protocols and in the execution of the research, rather than just at the final communication and reporting phase. We use a large study of potential radionuclide levels in marine biota around Amchitka Island as a case study. Amchitka Island, in the Aleutian Island Chain of Alaska, was the site of three underground nuclear tests (1965-1971). The overall objective of the biological component of the study was to collect a range of marine biota for radionuclide analysis that could provide data for assessing current food safety and provide a baseline for developing a plan to monitor human and ecosystem health in perpetuity. Stakeholders, including regulators (State of Alaska), resource trustees (US Fish and Wildlife Service, State of Alaska), representatives of the Aleut and Pribilof Island communities, the Department of Energy (DOE), and others, were essential for plan development. While these stakeholders were included in the initial problem formulation and approved science plan, we also included them in the refinement of protocols, selection of bioindicators, selection of a reference site, choice of methods of collection, and in the execution of the study itself. Meetings with stakeholders resulted in adding (or deleting) bioindicator species and tissues, prioritizing target species, refining sampling methods, and recruiting collection personnel. Some species were added because they were important subsistence foods for the Aleuts, and others were added because they were ecological equivalents to replace species deleted because of low population numbers. Two major refinements that changed the research thrust were (1) the inclusion of Aleut hunters and fishers on the biological expedition itself to ensure that subsistence foods and methods were represented, and (2) the addition of a fisheries biologist on a NOAA research trawler to allow sampling of commercial fishes. Although the original research design called for the collection of biota by Aleut subsistence fishermen, and by a commercial fishing boat, the research was modified with continued stakeholder input to actually include Aleuts and a fisheries biologist on the expeditions to ensure their representation. The inclusion of stakeholders during the development of protocols and the research itself improved the overall quality of the investigation, while making it more relevant to the interested and affected parties. Final responsibility for the design and execution of the research and radionuclide analysis rested with the researchers, but the process of stakeholder inclusion made the research more valuable as a source of credible information and for public policy decisions.

With the ending of the Cold War, the US Department of Energy is responsible for the remediation of radioactive waste and disposal of land no longer needed for nuclear material production or related national security missions. The task of characterizing the hazards and risks from radionuclides is necessary for assuring the protection of health of humans and the environment. This is a particularly daunting task for those sites that had underground testing of nuclear weapons, where the radioactive contamination is currently inaccessible. Herein we report on the development of a Science Plan to characterize the physical and biological marine environment around Amchitka Island in the Aleutian chain of Alaska, where three underground nuclear tests were conducted (1965-1971). Information on the ecology, geology, and current radionuclide levels in biota, water, and sediment is necessary for evaluating possible current contamination and to serve as a baseline for developing a plan to ensure human and ecosystem health in perpetuity. Other information required includes identifying the location of the salt water/fresh water interface where migration to the ocean might occur in the future and determining groundwater recharge balances, as well as assessing other physical/geological features of Amchitka near the test sites. The Science Plan is needed to address the confusing and conflicting information available to the public about radionuclide risks from underground nuclear blasts in the late 1960s and early 1970s, as well as the potential for volcanic or seismic activity to disrupt shot cavities or accelerate migration of radionuclides into the sea. Developing a Science Plan involved agreement among regulators and other stakeholders, assignment of the task to the Consortium for Risk Evaluation with Stakeholder Participation, and development of a consensus Science Plan that dealt with contentious scientific issues. Involvement of the regulators (State of Alaska), resource trustees (U S Fish and Wildlife Service), representatives of the Aleut and Pribilof Island communities, and other stakeholders was essential for plan development and approval, although this created tensions because of the different objectives of each group. The complicated process of developing a Science Plan involved iterations and interactions with multiple agencies and organizations, scientists in several disciplines, regulators, and the participation of Aleut people in their home communities, as well as the general public. The importance of including all parties in all phases of the development of the Science Plan was critical to its acceptance by a broad range of regulators, agencies, resource trustees, Aleutian/Pribilof communities, and other stakeholders.

Enzyme solutions produced for commercial purposes unrelated to waste management have the potential for reducing the volume of wastes in streams containing cellulose, lipid and protein materials. For example, the authors have shown that cellulases used in denim production and in detergent formulations are able to digest cellulose-containing sorbents and other cellulose-based wastes contaminated either with crude oil or with radionuclides. This presentation describes the use of one such enzyme preparation (Rapidase{trademark}) for the degradation of cotton sorbents intentionally contaminated with low levels of plutonium. This is part of a feasibility study to determine if such treatments have a role in reducing the volume of low level and transuranic wastes to minimize the amount of radionuclide-contaminated waste that must be disposed of in secured storage areas.