Browsing by Author "Xu, Jun"

Now showing 1 - 4 of 4
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    Additional Molecular Evidence that The Royal Palm is Probably a Turkey Breed
    Smith, Edward J.; Xu, Jun; Adikari, J. (2019-07-09)
    In earlier investigations, we reported the uniqueness of Royal Palm from other commonly raise heritage turkeys. Here, we provide evidence from screening using primers specific for the Melanocortin 1 (MC1R) Receptor gene (located on turkey chromosome 13, accession number NC_015023). Five heritage strains, including Broad Breasted Bronze (48), Blue Slate (40), Midget White (40), Royal Palm (45), and Spanish Black (48) were included in the analyses of approximately 3300 base pairs of the MC1R gene. Seven SNPs were identified and validated. Among the haplotypes identified, only Royal Palm had unique haplotypes. When combined with previous investigations, we believe that the Royal Palm may be a breed and not a strain. It may therefore be the most viable resource for introgression with a goal of genetic improvement.
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    A Framework for Site Analysis with Emphasis on Feng Shui and Contemporary Environmental Design Principles
    Xu, Jun (Virginia Tech, 2003-09-30)
    This research proposes a new site analysis methodology in the form of an integrated framework. The framework separates the site analysis process into different models, incorporates each model, and considers the interaction between them. The most important models are the environmental models (climate, geology, hydrology, topography, and vegetation models), social-cultural models, economic models, and infrastructure models. Each model also contains several important factors. The study identifies and organizes environmental factors within the framework that influence site analysis and design. Based on the applicability of feng shui principles and their interpretations into measurable factors, this research compares and incorporates feng shui and contemporary environmental design theories, and summarizes essential environmental factors. The emphasis on environmental factors from these models may lead to a better understanding of the relationships between humankind and the natural environment. The proposed framework is implemented into a computer simulation program, titled SiteOne, to demonstrate the concepts and ideas, with an emphasis on environmental factors. This research uses the town of Reston in Fairfax County, Virginia, as the study area because of the availability of information. SiteOne analyzes a range of alternatives and then derives solutions from the suggested site conditions in the form of GIS maps. There are various modules that make up the prototype system: namely an analysis module, a database module, and a result generation module. SiteOne helps professionals collect a wide range of information and select corresponding criteria in the early stages of design. It also provides visual analysis based on selected criteria and models. Therefore, it can act as an educational knowledge component for professionals as well as the general public.
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    High-performance inertial impaction filters for particulate matter removal
    Zhang, Xiaowei; Zhang, Wei; Yi, Mingqiang; Wang, Yingjie; Wang, Pengjun; Xu, Jun; Niu, Fenglei; Lin, Feng (Springer Nature, 2018-03-19)
    Airborne particulate matter (PM) is causing more and more serious air pollution and threatening the public health. However, existing air filter technologies with the easy-to-block manner can rarely meet the requirements of high-performance PM filters. Here we propose a conceptually new type of inertial impaction filters for rapidly high-efficiency PM removal. Under the airflow velocity of 8.0 m/s, the real inertial impaction filters show high PM removal efficiencies of up to 97.77 +/- 1.53% and 99.47 +/- 0.45% for PM2.5 and PM10, respectively. Compared with the traditional air filters reported previously, the inertia impaction filters exhibit extremely low pressure drop of 5-10 Pa and high quality factor (QF) values of 0.380 Pa-1 and 0.524 Pa-1 for PM2.5 and PM10, respectively. These greatly improved QF values are achieved through a series of inertial separation processes. The feature dimension of filtration channel is dozens of times larger than PM average size, which greatly decreases airflow resistance. Particularly, this inertial structure can be made of various types of materials, which shows great potential for low-cost fabrication of large-area devices. As a stand-alone device or incorporated with the existing PM air filter, this inertial impaction filter will bring great benefits to the public health.
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    Transitions -- Design a Courthouse
    Xu, Jun (Virginia Tech, 1999-05-10)
    The project is a courthouse designed in the town of Blacksburg. It will not only provides an important and functional public building in the local architectural history, but also improves the urban situation and zoning separation of the town. The corner condition of the project is the focus point of the design, with the architectural interpretation of transition of the scale, material, and the path. The hierarchy of the civic spirit is considered in the façade as well as in the courtrooms themselves.