3,168 research outputs found

    Analysis of an oscillating plate coupled with fluid

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    Thesis (M.S.) University of Alaska Fairbanks, 2013The mechanical vibration of an oscillating cantilever plate is studied to determine the interaction of a plate coupled with air and with water. Experimental data was collected and analyzed using multiple methods including Fast Fourier Transform, wavelet analysis, and the Hilbert-Huang Transform (HHT) to characterize the behavior of the plate. The HHT is able to process nonlinear and nonstationary signals and provides more meaningful information compared to the traditionally used Fourier transform for similar applications. The HHT was found to be appropriate and more descriptive for the analysis of coupled fluid-structure systems. Digital Particle Image Velocimetry (DPIV) was also used to analyze the circulation and energy transferred to the fluid.Chapter 1. Introduction -- Chapter 2. Method -- 2.1. Equipment setup -- 2.2. Data collection parameters -- 2.3. Analysis methods -- 2.3.1. Fast Fourier transform -- 2.3.2. Wavelet -- 2.3.3. Hilbert-Huang transform -- 2.3.4. Digital particle image velocimetry -- Chapter 3. Experiment -- 3.1. Design of experiment -- Chapter 4. Analysis -- 4.1. Raw data -- 4.2. Data analysis -- 4.2.1. Waveform -- 4.2.2. Fast Fourier transform -- 4.2.3. Wavelet -- 4.2.4. Hilbert-Huang transform -- 4.2.5. Digital particle image velocimetry -- Chapter 5. Conclusions -- References

    Ophyiulus in Victoria: results of millipede surveys from south-eastern Australia

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    The composition and ecology of the millipede fauna of Victoria remain poorly understood. We collected millipedes as part of a series of ecological arthropod surveys across south-eastern Australia, focusing mainly on Victoria. These samples almost exclusively contained millipedes from the introduced order Julida. We pursued species identification of the julids when it became apparent there were species other than the well-recorded Ommatoiulus moreleti (Lucas, 1860) (Portuguese millipede) in the samples. The majority of specimens were O. moreleti, but we also detected at least one species of Cylindroiulus Verhoeff, 1894, as well as an Ophyiulus Berlese, 1884, species, specimens of which have been identified as Ophyiulus cf. targionii. These are the first Ophyiulus records for Victoria to our knowledge. We present preliminary data on the abundance through the year of Ophyiulus. This is the first study to examine this species in Victoria and little is currently known about its likely impact on agriculture or on native species. Monitoring and research of the species in the future is therefore warranted

    Carbon Free Boston: Technical Summary

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    Part of a series of reports that includes: Carbon Free Boston: Summary Report; Carbon Free Boston: Social Equity Report; Carbon Free Boston: Buildings Technical Report; Carbon Free Boston: Transportation Technical Report; Carbon Free Boston: Waste Technical Report; Carbon Free Boston: Energy Technical Report; Carbon Free Boston: Offsets Technical Report; Available at http://sites.bu.edu/cfb/OVERVIEW: This technical summary is intended to argument the rest of the Carbon Free Boston technical reports that seek to achieve this goal of deep mitigation. This document provides below: a rationale for carbon neutrality, a high level description of Carbon Free Boston’s analytical approach; a summary of crosssector strategies; a high level analysis of air quality impacts; and, a brief analysis of off-road and street light emissions.Published versio

    UK public perceptions of shale gas hydraulic fracturing:The role of audience, message and contextual factors on risk perceptions and policy support

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    There is growing recognition of the need to understand public attitudes to energy sources, such as shale gas, and to feed these into decision-making. This study represents the first detailed UK experimental survey of public perceptions of shale gas fracking, including analysis of the effects of different messages and the relative influence of different audience, message and contextual factors on support and risk perceptions in respect of shale gas fracking. Using an online survey (N = 1457) of the UK public, we find considerable ambivalence about shale gas, but also greater awareness of potential risks than benefits. Prior knowledge is associated with more favourable attitudes, although demographics, political affiliation and environmental values are strongest influences on perceptions. When provided with environmental or economic information about shale gas, participants became more positive – irrespective of their prior values or whether information is framed in terms of losses or gains. As expected, prior attitudes predict how information is received, with more attitude change amongst the most ambivalent respondents. We conclude that additional information about shale gas is more likely to be effective changing attitudes if focussed on this ’undecided’ group. Studies of this type are important for policy makers and industry alike

    Interaction of preimplantation factor with the global bovine endometrial transcriptome

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    Preimplantation factor (PIF) is an embryo derived peptide which exerts an immune modulatory effect on human endometrium, promoting immune tolerance to the embryo whilst maintaining the immune response to invading pathogens. While bovine embryos secrete PIF, the effect on the bovine endometrium is unknown. Maternal recognition of pregnancy is driven by an embryo-maternal cross talk, however the process differs between humans and cattle. As many embryos are lost during the early part of pregnancy in cattle, a greater knowledge of factors affecting the embryo-maternal crosstalk, such as PIF, is needed to improve fertility. Therefore, for the first time, we demonstrate the effect of synthetic PIF (sPIF) on the bovine transcriptome in an ex vivo bovine endometrial tissue culture model. Explants were cultured for 30h with sPIF (100nM) or in control media. Total RNA was analysed via RNA-sequencing. As a result of sPIF treatment, 102 genes were differentially expressed compared to the control (Padj<0.1), although none by more than 2-fold. The majority of genes (78) were downregulated. Pathway analysis revealed targeting of several immune based pathways. Genes for the TNF, NF-ÎşB, IL-17, MAPK and TLR signalling pathways were down-regulated by sPIF. However, some immune genes were demonstrated to be upregulated following sPIF treatment, including C3. Steroid biosynthesis was the only over-represented pathway with all genes upregulated. We demonstrate that sPIF can modulate the bovine endometrial transcriptome in an immune modulatory manner, like that in the human endometrium, however, the regulation of genes was much weaker than in previous human work

    Tetrahymena Genome Database (TGD): a new genomic resource for Tetrahymena thermophila research

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    We have developed a web-based resource (available at ) for researchers studying the model ciliate organism Tetrahymena thermophila. Employing the underlying database structure and programming of the Saccharomyces Genome Database, the Tetrahymena Genome Database (TGD) integrates the wealth of knowledge generated by the Tetrahymena research community about genome structure, genes and gene products with the newly sequenced macronuclear genome determined by The Institute for Genomic Research (TIGR). TGD provides information curated from the literature about each published gene, including a standardized gene name, a link to the genomic locus in our graphical genome browser, gene product annotations utilizing the Gene Ontology, links to published literature about the gene and more. TGD also displays automatic annotations generated for the gene models predicted by TIGR. A variety of tools are available at TGD for searching the Tetrahymena genome, its literature and information about members of the research community

    Metastatic Esophageal Carcinoma Cells Exhibit Reduced Adhesion Strength and Enhanced Thermogenesis

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    Despite continuous improvements in multimodal therapeutic strategies, esophageal carcinoma maintains a high mortality rate. Metastases are a major life-limiting component; however, very little is known about why some tumors have high metastatic potential and others not. In this study, we investigated thermogenic activity and adhesion strength of primary tumor cells and corresponding metastatic cell lines derived from two patients with metastatic adenocarcinoma of the esophagus. We hypothesized that the increased metastatic potential of the metastatic cell lines correlates with higher thermogenic activity and decreased adhesion strength. Our data show that patient-derived metastatic esophageal tumor cells have a higher thermogenic profile as well as a decreased adhesion strength compared to their corresponding primary tumor cells. Using two paired esophageal carcinoma cell lines of primary tumor and lymph nodes makes the data unique. Both higher specific thermogenesis profile and decreased adhesion strength are associated with a higher metastatic potential. They are in congruence with the clinical patient presentation. Understanding these functional, biophysical properties of patient derived esophageal carcinoma cell lines will enable us to gain further insight into the mechanisms of metastatic potential of primary tumors and metastases. Microcalorimetric evaluation will furthermore allow for rapid assessment of new treatment options for primary tumor and metastases aimed at decreasing the metastatic potential

    Categorizing the severity of paralytic shellfish poisoning outbreaks in the Gulf of Maine for forecasting and management

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    Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 103 (2014): 277-287, doi:10.1016/j.dsr2.2013.03.027.Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far these forecasts have used terms such as “significant”, “moderately large” or “moderate” to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each year’s PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined (“Level 1: Limited”, “Level 2: Moderate”, and “Level 3: Extensive”) each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts.Research support provided through the Woods Hole Center for Oceans and Human Health, National Science Foundation (NSF) Grants OCE-0430724, and OCE-0911031; and National Institute of Environmental Health Sciences (NIEHS) Grant 1-P50-ES012742-01, the ECOHAB Grant program through NOAA Grant NA06NOS4780245, and the PCM HAB Grant program through NOAA Grant NA11NOS4780023

    Navier-Stokes Analysis of a High Wing Transport High-Lift Configuration with Externally Blown Flaps

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    Insights and lessons learned from the aerodynamic analysis of the High Wing Transport (HWT) high-lift configuration are presented. Three-dimensional Navier-Stokes CFD simulations using the OVERFLOW flow solver are compared with high Reynolds test data obtained in the NASA Ames 12 Foot Pressure Wind Tunnel (PWT) facility. Computational analysis of the baseline HWT high-lift configuration with and without Externally Blown Flap (EBF) jet effects is highlighted. Several additional aerodynamic investigations, such as nacelle strake effectiveness and wake vortex studies, are presented. Technical capabilities and shortcomings of the computational method are discussed and summarized

    A fuzzy synthetic evaluation of the challenges of smart city development in developing countries

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    © 2020, Emerald Publishing Limited. Purpose: This study presents a fuzzy synthetic evaluation of the challenges of smart city realisation in developing countries, using Nigeria as a case study. By defining and delineating the problems faced by the country, more viable directions to attaining smart city development can be achieved. Design/methodology/approach: The study adopted a post-positivist philosophical stance with a deductive approach. A structured questionnaire was used to gather data from built environment professionals involved in the delivery of Nigerian public infrastructures. Six dimensions of the challenges of smart cities were identified from literature and explored. They are governance, economic, social, technological, environmental and legal issues. Data gathered were analysed using Cronbach alpha test for reliability, Shapiro-Wilks test for normality, Kruskal-Wallis H-test for consistency and fuzzy synthetic evaluation test for the synthetic evaluation of the challenges of smart city attainment. Findings: The findings revealed that all six assessed dimensions have a significant impact on the attainment of smart cities in Nigeria. More specifically, issues relating to environmental, technological, social and legal challenges are more prominent. Originality/value: The fuzzy synthetic approach adopted provides a clear, practical insight on the issues that need to be addressed before the smart city development can be attained within developing countries
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