671 research outputs found

    Theoretical prediction of airplane stability derivatives at subcritical speeds

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    The theoretical development and application is described of an analysis for predicting the major static and rotary stability derivatives for a complete airplane. The analysis utilizes potential flow theory to compute the surface flow fields and pressures on any configuration that can be synthesized from arbitrary lifting bodies and nonplanar thick lifting panels. The pressures are integrated to obtain section and total configuration loads and moments due side slip, angle of attack, pitching motion, rolling motion, yawing motion, and control surface deflection. Subcritical compressibility is accounted for by means of the Gothert similarity rule

    Tuberculosis in Pregnancy

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    Tuberculosis (TB) during pregnancy and in the perinatal period was once considered to be an infrequent event in the United States. After a decade of steady decline, however, the disease has begun a resurgence. According to the CDC, a 20% increase in the number of reported cases occurred between 1985 and 1992. The factors associated with this increase are the emergence of human immunodeficiency virus (HIV) infection, the development of drug-resistant organisms, substance abuse, homelessness, and immigration. Environmental factors promoting transmission can be found in overcrowded areas such as correctional facilities, nursing homes, hospitals, and migrant-worker camps. For a large number of medically underserved women, the obstetrician is the only interface with medical care, as most of these patients do not have primary-care providers. It is important, therefore, that health-care providers recognize the clinical symptoms of TB and follow the recognized guidelines for antenatal screening for TB because the omission of these steps can lead to potentially disastrous sequelae in the fetus and neonate

    High-Performance Interactive Scientific Visualization With Datoviz via the Vulkan Low-Level GPU API

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    We reported initial work towards a new fast and scalable scientific visualization technology that leverages the Vulkan API to achieve unprecedented performance through GPUs. This technology is implemented in a C/C++ library called Datoviz that offers an intermediate-level API for scientific visualization libraries and software. Datoviz provides a unified graphics stack for 2-D, 3-D, graphical user interfaces, and natively supports efficient interactions between rendering and general-purpose GPU computing. A major direction of development is to investigate the integration of Datoviz as a low-level backend of a future version of VisPy, a popular Python scientific plotting librar

    Quantitative characterization of the x-ray imaging capability of rotating modulation collimators with laser light

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    We developed a method for making quantitative characterizations of bi-grid rotating modulation collimators (RMC ’s) that are used in a Fourier transform x-ray imager. With appropriate choices of the collimator spacings, this technique can be implemented with a beam-expanded He -Ne laser to simulate the plane wave produced by a point source at infinity even though the RMC ’s are diffraction limited at the He -Ne wavelength of 632.8 nm. The expanded beam passes through the grid pairs at a small angle with respect to their axis of rotation, and the modulated transmission through the grids as the RMC ’s rotate is detected with a photomultiplier tube. In addition to providing a quantitative characterization of the RMC ’s, the method also produces a measured point response function and provides an end-to-end check of the imaging system. We applied our method to the RMC ’s on the high-energy imaging device (HEIDI) balloon payload in its preflight configuration. We computed the harmonic ratios of the modulation time profile from the laser measurements and compared them with theoretical calculations, including the diffraction effects on irregular grids. Our results indicate the 25-in. (64-cm) x-ray imaging optics on HEIDI are capable of achieving images near the theoretical limit and are not seriously compromised by imperfections in the grids

    Sunplanter

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    Although the cost of solar technology has been reduced by nearly seventy percent in the last ten years, the cost of implementing solar panels for residential and commercial use has remained stagnant. Due to the lack of affordable, easily installable solar panel systems on residential properties, the goal of our Senior Design Project is to design a stand-alone solar tracking structure. Since the system is stand-alone, it can be easily implemented on a wide range of properties in most areas of California. Our design for the support of the solar tracking system is a two-pole structure, with a wide base under each pole to eliminate the need for a deep foundation. An electric gearmotor system will drive the rotational motion of the solar tracking function, due to its high power output and relatively affordable cost. A hydraulic damping and blocking system was incorporated to precisely control rotational motion. After testing the system for both tracking and static operation, an 11.4% increase power production was observed. Sunplanter solar tracking systems have the potential to provide a financially viable investment opportunity for customers while having a positive impact on the environment

    High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor

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    The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. © 2014 Bill et al

    Reframing human rights: the global network of moral conservative homeschooling activists

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    In this article, we investigate the composition and actions of a principled issue network within the field of human rights that uses rights-claims to pursue traditionalist goals: the moral conservative pro-homeschooling network. We analyse the rising importance of homeschooling within the global moral conservative movement and examine the transnationalization of pro-homeschooling advocacy. We show that the transnational homeschooling advocacy network, while not successful in court cases, has managed to establish home education as part of a global conservative agenda and has made incursions into redefining the terms of the debate within international organizations. Moral conservative homeschooling advocates use a vocabulary of rights and freedoms, and even of moral pluralism, but in the conservative reading human rights are reframed and used to defend a pro-family agenda that establishes the patriarchal family as the ultimate source of authority and the primary carrier of rights
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