7,406 research outputs found

    Understanding Cigarette Butt Littering Behavior on a Public Beach: A Case Study of Jekyll Island

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    Conservation of natural resources and promotion of family-friendly tourism activities are vital to Jekyll Island. As it is stated in the Jekyll Island Authority (JIA) Master Plan “Jekyll Island is a unique, state-owned barrier island that balances conserving and preserving natural, historic, and cultural resources with providing accessible, affordable recreation, vacation, and education opportunities for the people of Georgia and beyond” (Jekyll Island Authority, 2014b, p. 4). The JIA has reported approximately 1 million people visit the island annually (Jekyll Island Authority, 2015). As such, tourism is instrumental to Jekyll Island’s economy, and that tourism contributes to the overall economy of Glynn County. According to a report put out by Glynn County (2014) the unemployment rate in the county is consistently within one point of the rest of the state, primarily due to tourism

    Autonomous support for microorganism research in space

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    A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing

    SONTRAC: an imaging spectrometer for solar neutrons

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    An instrument capable of unambiguously determining the energy and direction of incident neutrons has important applications in solar physics-as well as environmental monitoring and medical/radiological sciences. The SONTRAC (SOlar Neutron TRACking) instrument is designed to operate in the neutron energy range of 20-250 MeV. The measurement principle is based on non-relativistic double scatter of neutrons off ambient protons (n-p scattering) within a block of densely packed scintillating fibers. Using this double-scatter mode it is possible to uniquely determine neutron energy and direction on an event-by-event basis. A fully operational science model of such an instrument has been built using 300 μm (250 μm active) scintillating fibers. The science model consists of a 5×5×5 cm cube of orthogonal plastic scintillating fiber layers. Two orthogonal imaging chains, employing image intensifiers and CCD cameras, allow full 3-dimensional reconstruction of scattered proton particle tracks. We report the results of the science model instrument calibration using 35-65 MeV protons. The proton calibration is the first step toward understanding the instrument response to n-p scatter events. Preliminary results give proton energy resolution of 2% (6%) at 67.5 (35) MeV, and angular resolution of 2° (4.5°) at 67.5 (35) MeV. These measurements are being used to validate detailed instrument simulations that will be used to optimize the instrument design and develop quantitative estimates of science return. Based on the proton calibration, neutron energy and angular resolution for a 10×10×10 cm version of SONTRAC is expected to be ~5% an

    HOUSEHOLDS' EXPERIENCES WITH THE RED IMPORTED FIRE ANT IN SOUTH CAROLINA

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    The red imported fire ant (Solenopsis invicta), abbreviated as RIFA, is believed to have been brought by accident to Mobile, Alabama in the 1930s via ship ballast from South America. The RIFA was first reported in Charleston and Orangeburg counties in South Carolina in 1952 and has since spread to all 46 counties in the state. The RIFA has had adverse impacts on the environments it has infested. In natural environments, the young of ground-nesting insects, reptiles, birds and mammals are subject to RIFA predation. In agriculture, the RIFA damages crops and livestock. The RIFA poses a health threat to humans, as it is aggressive and has a venomous sting. To learn more about the current impacts of the RIFA, a random sample of South Carolina households was conducted between November 1998 and January 1999. This report summarizes the survey results.Environmental Economics and Policy,

    Effects of Arctic Alaska Oil Development on Brant and Snow Geese

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    Black brant (Branta bernicla nigricans) and lesser snow geese (Chen c. caerulescens) breeding in and near arctic Alaska oil fields could be affected by oil development actions such as releases of contaminants, alteration of tundra surfaces, creation of impoundments, and human activities. These actions could affect geese directly (e.g., through oil spills) or indirectly (e.g., by altering food supplies or predator populations). Studies to date indicate no changes in the distribution, abundance, or reproduction of these geese that clearly can be attributed to development; rather, their numbers and recruitment have responded in the oil fields, as elsewhere, mainly to weather and predation. When snowmelt in spring is later than usual, the birds postpone or forego nesting, with consequent diminishment in recruitment. Predation by arctic foxes (Alopex lagopus), glaucous gulls (Larus hyperboreus), and grizzly bears (Ursus arctos) sometimes causes substantial losses of eggs and young, and predation by ravens (Corvus corax) has also been observed. Development-related changes in weather (microclimate) and loss of feeding habitat have involved small percentages of the total areas traditionally used, and populations of the birds probably have not been affected by these changes. Some studies and observations suggest that development has elevated local populations of some predators, but whether the level of predation on geese has in consequence risen above that which would have occurred in the absence of development is unknown; further investigation of this mechanism of potential impact is recommended.La bernache noire (Branta bernicla nigricans) et la petite oie des neiges (Chen c. caerulescens) nichant dans les champs pétrolifères de l'Alaska ou à proximité pourraient être affectées par des actes reliés à l'exploitation pétrolière, tels que le déversement d'agents de pollution, les modifications à la toundra de surface, la création de bassins, et par l'activité humaine. Ces interventions pourraient affecter les oies de façon directe (p. ex., par le biais de déversements de pétrole) ou indirecte (p. ex., en modifiant l'approvisionnement alimentaire ou les populations de prédateurs). Jusqu'à l'heure actuelle, les études ne montrent pas de changements dans la distribution, l'abondance ou la reproduction de ces oies, dont la cause puisse être clairement attribuée à l'exploitation; dans les champs pétrolifères, le nombre d'oies et leur augmentation ont surtout réagi, comme ailleurs, au climat et à la prédation. Quand la fonte des neiges printanière a lieu plus tard que d'habitude, les oiseaux retardent la ponte ou s'abstiennent de pondre, ce qui entraîne moins d'augmentation. La prédation par le renard arctique (Alopex lagopus), le goéland bourgmestre (Larus hyperboreus) et le grizzli (Ursus arctos) entraîne parfois d'importantes pertes d'oeufs et d'oisons, et on a également observé des cas de prédation par le corbeau (Corvus corax). Des modifications climatiques (microclimat) reliées à l'exploitation et la perte d'aires d'alimentation ne concernent qu'un faible pourcentage du total des zones utilisées traditionnellement, et les populations d'oiseaux n'ont probablement pas été affectées par ces changements. Quelques études et observations suggèrent que la mise en valeur a fait augmenter les populations locales de certains prédateurs, mais on ne sait pas si le niveau de prédation de l'oie qui en a résulté était plus élevé qu'il ne l'aurait été en l'absence de la mise en valeur; on recommande que le mécanisme de ces retombées potentielles soit étudié plus à fond

    Bioaccumulation and biomagnification of microplastics in marine organisms: a review and meta-analysis of current data

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    Microplastic (MP) contamination has been well documented across a range of habitats and for a large number of organisms in the marine environment. Consequently, bioaccumulation, and in particular biomagnification of MPs and associated chemical additives, are often inferred to occur in marine food webs. Presented here are the results of a systematic literature review to examine whether current, published findings support the premise that MPs and associated chemical additives bioaccumulate and biomagnify across a general marine food web. First, field and laboratory-derived contamination data on marine species were standardised by sample size from a total of 116 publications. Second, following assignment of each species to one of five main trophic levels, the average uptake of MPs and of associated chemical additives was estimated across all species within each level. These uptake data within and across the five trophic levels were then critically examined for any evidence of bioaccumulation and biomagnification. Findings corroborate previous studies that MP bioaccumulation occurs within each trophic level, while current evidence around bioaccumulation of associated chemical additives is much more ambiguous. In contrast, MP biomagnification across a general marine food web is not supported by current field observations, while results from the few laboratory studies supporting trophic transfer are hampered by using unrealistic exposure conditions. Further, a lack of both field and laboratory data precludes an examination of potential trophic transfer and biomagnification of chemical additives associated with MPs. Combined, these findings indicate that, although bioaccumulation of MPs occurs within trophic levels, no clear sign of MP biomagnification in situ was observed at the higher trophic levels. Recommendations for future studies to focus on investigating ingestion, retention and depuration rates for MPs and chemical additives under environmentally realistic conditions, and on examining the potential of multi-level trophic transfer for MPs and chemical additives have been made

    Composite fastener for use in high temperature environments

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    A fastener includes a composite body and a metal coupling attached to the body. The metal coupling includes an attachment structure to connect the fastener to an external structure. An assembly of components includes a first metallic component having a first coefficient of thermal expansion, a second non-metallic component having a second coefficient of thermal expansion different from the first thermal expansion and having a groove that receives a fastener that extends between the groove and the second component, the fastener slidably engaging the groove to accommodate relative expansion between the components

    An Intensive Cultural Resources Survey of 107 Acres Along Galm Road, San Antonio, Bexar County, Texas

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    In December 2016, the Northside Independent School District (Client) contracted with Raba Kistner Environmental, Inc. (RKEI) to perform a cultural resources pedestrian survey within a 107-acre tract near Galm Road in San Antonio, Bexar County, Texas. The purpose of this survey was to determine whether cultural resources were located within the Area of Potential Effects (APE), and if feasible, assess their significance and eligibility for designation as State Antiquities Landmarks (SALs) and for inclusion in the National Register of Historic Places (NRHP). The project was sponsored by the Client and the owner of the project is currently George Weimer (soon to be owned by the Client). Since the area of potential effects (APE) is owned by a political subdivision of the state, the project falls under the Antiquities Code of Texas, as administered by the Texas Historical Commission (THC). Additionally, the APE is 2.5 kilometers to the southeast of Government Canyon State Natural Area. The field work was carried out between January 10 and 13, 2017 under Texas Antiquities Committee Permit No. 7866, issued to Kristi M. Nichols, who served as Principal Investigator. Mark Luzmoor served as the Project Archaeologist and Chris Murray, Richard Sample, Chris Matthews, and Kendra Brownlow assisted during the field work. Background research revealed that no previously recorded archaeological sites are located within the boundary of the APE. However, there are five archaeological sites within a 1-kilometer radius of the APE. In total, 19 shovel tests (STs) were excavated within the APE. Surface visibility was around 80% throughout the APE. Approximately 75% of the APE was open-plowed fields, with the other 25% located in fairly thick underbrush. During the pedestrian survey, 25 isolated artifacts were encountered within the plowed fields of the APE. These included secondary and tertiary flakes, bifaces, and utilized flakes; only the tools were collected. A historic bottle dump also was encountered during the pedestrian survey on the eastern end of the APE. The bottles date to the middle of the twentieth century. Two shovel tests (ST 3 & 5) were positive for cultural material in the top 20 centimeters below surface (cmbs) (two pieces of debitage and one burned rock). 41BX2162 was designated as a multi-component archaeological site due to the large amount of surface finds, the two positive STs, and the historic bottle dump, all along the eastern end of the APE. However, no cultural deposits were encountered beneath 20 cmbs, the majority of the cultural material was recorded on the surface, and no diagnostic prehistoric material was encountered. Thus, RKEI finds that the site lacks research potential and recommends no further archaeological work within the project boundaries. All field records generated by this project will be curated in accordance with the Texas Archaeology Research Laboratory guidelines
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