712 research outputs found

    The build, operate, and transfer ("BOT") approach to infrastructure projects in developing countries

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    Build, operate and transfer (BOT) projects are exceedingly complex from both a financial and a legal point of view. They require an extended period of time to develop and negotiate. If a country is not able to finance all of its needed infrastructure on the basis of budgetary resources or sovereign borrowings, the BOT approach is an option to be considered. A BOT project appears to provide some"additionality"in tapping sources of private sector financing which otherwise might not be available. The sponsors'commitment of substantial equity to a project assures that they will also remain committed to the project's successful operation over the concession period. Their investment provides a strong incentive to have the project perform above its minimum expectations. Likewise, having the design, implementation and operation of a BOT project largely in the hands of the private sector may provide economies and efficiencies that will balance out or even outweight the higher financing costs of non sovereign borrowing and equity investment. The BOT approach appears to be a useful possible alternative to the conventional financing and operation of infrastructure projects in developing countries.Municipal Financial Management,Public Sector Economics&Finance,Housing Finance,Environmental Economics&Policies,Banks&Banking Reform

    Lethal Effects of Leaf Leachate from the Non-Native Invasive Shrub Amur Honeysuckle (Lonicera maackii) on a Model Aquatic Organism (Hyalella azteca)

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    The invasive shrub Lonicera maackii (Amur honeysuckle) is a problematic species in the eastern United States and there is growing evidence that materials from this species have toxic effects on some organisms. We used a sequence of microcosm bioassays to assess the influence of L. maackii leaf leachate on the macroinvertebrate Hyalella azteca, which is a standard aquatic organism for toxicity assessment. In a laboratory setting, H. azteca were exposed to a leaf leachate dilution series (6.25%, 12.5%, 25%, 50%, 100%) in 48-h toxicity tests. This was repeated throughout the growing season to assess the potential for changes in leaf toxicity due to phenology. Strong toxic effects were found when H. azteca was exposed to a L. maackii leachate from autumn (P \u3c 0.05) and, in fact, all organisms died when exposed to any level of concentration in most trials. Mean percent survival also decreased significantly in all dilutions in the spring (P \u3c 0.05 for all treatments); however, little toxicity was detected in growing season trials. These results suggest (a) strong toxic effects of L. maackii foliage on a model aquatic organism that (b) varies throughout the year, potentially in relationship to biochemical changes associated with phenology

    Lethal and Sublethal Effects of Novel Terrestrial Subsidies from an Invasive Shrub (Lonicera maackii) on Stream Macroinvertebrates

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    The biology of headwater streams is intimately linked to that of the surrounding terrestrial environment through organic matter subsidies. Lonicera maackii, an invasive shrub that is becoming abundant in headwater stream riparian areas, deposits substantial quantities of organic matter into the aquatic system. This organic material has allelopathic effects on terrestrial plants and insects, and a growing body of work suggests strong connections between L. maackii invasion and aquatic biota. Lonicera maackii deposits fruit and flowers in quantities and timings that are unique, and we tested the hypothesis that these subsidies would negatively affect survival and growth of laboratory-cultured Hyalella azteca and field-collected Anthopotamus verticis and Allocapnia spp. Invertebrates were exposed to a gradient of fruit (reference sediment + 0, 0.31, 0.62, 1.25, or 2.5 g dry mass [DM]) and flower (reference sediment + 0, 0.30, 0.60, 1.2, or 2.4 g DM) biomass in laboratory and field sediment exposure tests. Hyalella azteca survival was significantly reduced by exposure to L. maackii fruit in the laboratory and in the field exposures, and a negative effect was observed for A. verticis (p\u3c 0.05). Lonicera maackii flower biomass was associated with negative effects on survival of H. azteca in the field and laboratory exposures and of A. verticis in the laboratory exposure. During the laboratory exposures, dissolved O2 (DO) and pH were /L and 5.5, respectively. In the field exposures, DO and pH were comparable to stream conditions during fruit exposures, declining significantly with increasing flower biomass. Our results suggest that L. maackii fruit and flowers, novel subsidies in these systems, can negatively affect benthic organism survival and growth. Research focused on verifying this novel subsidy hypothesis for L. maackii and other species could enhance our understanding of invasion biology and terrestrial–aquatic linkages

    Using mlearning in the education of radiation science students

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    Radiation science is a highly visual field that is constantly evolving due to technological advances. Technology has significantly improved almost all aspects of the field over the past 10-15 years. These advances in technology have also played a significant role in the education of radiation science students didactically and clinically. The enormous increase in the capabilities of information technology provides the opportunity for educators to dramatically change their way of teaching.1 mLearning or mobile learning involves the use of mobile devices (i.e. personal digital assistants, smart phones, iPhones, iTouch, iPad, laptops and tablets) to enhance teaching and learning. The most significant advantage of mLearning is the mobility of the technology which allows for unlimited, immediate and continuous access to course materials. The goal of this initial research is to discuss the implementation of mobile learning, specifically through the use of the Apple iTouch, into the education of radiation science students

    The Ursinus Weekly, June 7, 1907

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    Baccalaureate sermon • Alumni oration • Junior oratorical contest • Class Day exercises • Commencement day • Editorial: The seniors; Vacation • Society notes • Personals • Donation to Library • Alumni • Charmidean banquet • Spiritual conference • Literary Supplement: Farewell song to the Class of 1907; The power of music; Uses of literature; The heredity of the twentieth century; Greater love hath no man; The history and plan of agricultural education; Jerry; A plea for the better management of railroadshttps://digitalcommons.ursinus.edu/weekly/2948/thumbnail.jp

    RECEIPT AND STORAGE ISSUES AT THE TMI-2 IRRADIATED FUEL STORAGE INSTALLATION

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    ABSTRACT In less than a year, up to 12 canisters of TMI-2 reactor fuel debris were loaded into each of 28 Dry Storage Containers (DSCs), and placed into interim storage at an Irradiated Spent Fuel Storage Facility (ISFSI) at the Idaho National Engineering and Environmental Laboratory (INEEL). Draining and drying the canisters, loading and welding the DSCs, shipping the DSCs 25 miles, and storing in the ISFSI initially required up to 3 weeks per DSC. Significant time efficiencies were achieved during the early stages, reducing the time to less than one week per DSC. These efficiencies were achieved mostly in canister draining and drying and DSC lid welding, and despite several occurrences that had to be resolved before continuing work. The ISFSI has been operated without issue since, with the exception that license basis monitoring has indicated an unusual pattern of season-and position-dependent hydrogen generation. This paper discusses some of the innovations and storage experiences for the first ISFSI designed for the storage of severely defected fuel. INTRODUCTION In the mid-to late 1980s the TMI-2 debris was packaged, transported to the INEEL, and stored in a water pool. Approximately 340 canisters of debris were removed from water storage, dried four at a time in a separate furnace, packaged into 29 larger steel canisters, and transported to the ISFSI. The TMI-2 ISFSI was the second operated by DOE, the first being the Fort Saint Vrain ISFSI near Denver. Preparation and storage of the TMI-2 fuel presented special challenges. First, the TMI-2 was required to be stored in the ISFSI before May 2001 as part of an INEEL fuel consolidation plan. Only one of the 29 Dry Storage Containers (DSCs) had been stored prior to June 2000. Most of the TMI-2 fuel debris consists of beds of porous chunks, granules, powders, and partial rods and assemblies packed within canisters lined with lightweight concrete, making the debris very difficult to dry. The ISFSI was positioned approximately 25 miles from the water pool where the canisters were stored. Structural considerations limited transport during cold weather and ISFSI loading during high winds. Long, cold winters and high winds are common at the INEEL. This paper describes the means by which these challenges were met and the unplanned occurrences were managed during the shipments. Finally it describes interesting monitoring results from the stored fuel, which suggests that some of the original design assumptions dealing with radiolysis were not realistic

    Radiolytic damage to freeze-dried human amniotic membrane

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    Radiation-sterilization at 25 and 35 kGy of freeze-dried human amniotic membranes caused degradative effects in the biologic dressing. The decrease in pH and increase in UV absorption showed that radiation may have caused possible radiolytic changes in this biomaterial. Total nitrogen content, tensile strength, and [H3]water-retention capacity of the irradiated membranes remained invariable. Molecular topography analysis by atomic force microscopy showed radiation-induced defrayment of the collagen fibers, the major structural protein in amnion

    The influence of riparian invasion by the terrestrial shrub Lonicera maackii on aquatic macroinvertebrates in temperate forest headwater streams

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    The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, and Trichoptera: EPT) and tolerant (Chironomidae) macroinvertebrate taxa. We found strong evidence of variation among macroinvertebrate communities across the invasion gradient (ANOSIM R = 0.215, P = 0.004) and particularly strong separation between one of our reference sites with minimal invasion and the site with the heaviest invasion. Analysis of EPT taxa indicated a significant overall effect and pairwise comparisons indicated that the site with the heaviest invasion had the lowest percentage of sensitive taxa (P \u3c 0.05). Our analysis of chironomids did not yield a statistically discernable effect, although the pattern of the data suggest higher dominance in the site with the heaviest invasion. These stream-scale results bolster prior laboratory and field experiments and provide evidence that terrestrial invasion of L. maackiiimpacts the benthic community present in headwater streams. These results provide impetus to re-focus stream management recommendations to include practices that control invasive plants in riparian forests
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