739 research outputs found
Numerically Enhanced Thermal Inspection of Shuttle Solid Rocket Motor Inhibitor/Liner/Fuel Bondline
The Solid Rocket Motors (SRM’s) for the Space Shuttle are fabricated by laying up and molding materials, such as insulation, which are joined using adhesives, the adhesives being set along with the materials in a final curing process for an entire motor segment at a time. The resulting structure (Fig. 1) has two important properties from the point of view of inspection: integrity of the adhesive joints (bondlines) is of great importance, and the structure cannot be disassembled for inspection prior to use. Of particular interest are disbonds producing small voids (delaminations) at the bondlines. Specific delaminations can be located in service hardware only by using NDE methods. This paper reports on the application of thermal methods for performing such inspections
Fine Scale Circulation Near Foxtrot in Hampton Roads, Virginia
During 1974 the Virginia Institute of Marine Science conducted a series of oceanographic, water quality and modeling studies for the outfall from the proposed Nansemond Wastewater Treatment Plant (VIMS, 1975). One of these studies included dye releases to determine the dispersion and transport of material discharged to Hampton Roads near Pig Point. These dye releases were made from the munitions loading piers known as Foxtrot .
The proposed outfall, as given in the Facilities Plan is located roughly one kilometer to the east-south-east of Foxtrot. Tidal circulation in Hampton Roads is quite complex and there was concern that the distribution patterns for material released at the two sites would differ appreciably. Therefore a fine scale circulation study was conducted in the vicinity of Foxtrot
On the use of drift bottle and seabed drifter data in coastal management
The use of drift bottle and seabed drifter information for use in coastal management is discussed. The drift bottle/seabed drifter portion of VIMS project MACONS (Mid Atlantic Continental Shelf) is described as an example of how a comprehensive survey using drift bottles and seabed drifters provides data useful for coastal management. The data from MACONS are analyzed to answer specific questions of interest to several different coastal managers: a manager siting a deep oil port, one siting a sewage outfall, a manager responsible for setting up emergency beach protection procedures before an accident occurs, and a manager responsible for the environmental quality of a particular small section of coastline
An investigation into the enantiomeric resolution of SbB amino alcohols and related compounds
Thesis (B.S.) in Chemistry--University of Illinois at Urbana-Champaign, 1982.Bibliography: leaf 37.Microfiche of typescript. [Urbana, Ill.] : Photographic Services, University of Illinois, U of I Library, [1982]. 2 microfiches (43 frames) : negative ; 11 x 15 cm
Countering Consumer Culture: Educating for Prophetic Imagination Through Communities of Practice
Thesis advisor: Jane E. ReganFew would dispute the notion that consumerism is a prevailing feature of American culture. The extent to which consumer culture dominates the way most people see the world makes imagining alternatives to consumerism almost impossible. This stultification of imagination is highly problematic. As it stands, consumer culture, measured by the principles of Catholic Social Teaching, demonstrably tends to inhibit human flourishing on personal, social, and global levels. There is a need to transform consumer culture in order to support human flourishing more robustly, and this barrenness of imagination impedes that transformation. This dissertation assumes that it is a task of teachers in faith to educate toward cultural alternatives that better support human flourishing. This task requires engaging in and developing what Scripture scholar Walter Brueggemann calls "prophetic imagination." The prophetic imagination involves both deconstructing the taken-for-granted dominant culture and entering into a community whose practices, values, and ideals effect an alternative culture. While here focused on consumer culture, this model of educating for prophetic imagination has broader applicability; it can also be used, for example, to challenge cultures of racism, sexism, and militarism. This education in imagination develops in what scholars of management Jean Lave and Etienne Wenger call "communities of practice." Jesus and his disciples model for Christians a community of practice that imagines and acts prophetically. Communities of practice that educate for prophetic imagination ought to measure their own imagination against Jesus's prophetic imagination, shaped by his understanding of the Reign of God. This portrait of communities of prophetic practice is fleshed out in an exploration of empirical studies of communities that engage learners and draw them into an imagination that re-shapes not only how they see what the world is but also how they envision what the world can be. Communities of practice that educate for prophetic imagination can foster the transformation of consumer culture into a culture that better supports human flourishing. In order to do so, however, they must start with an anthropology that adequately understands what flourishing entails. These communities ought to be attentive to three aspects of the human person that tend to be given short shrift in consumer culture: the person's role as a creative producer, the person's inherent relationality, and the person's need embrace finitude, the limitations of human capability. The Church should be utilizing communities of practice to overcome the sterility of imagination and contribute to a culture of what might be called humanizing plenitude. This culture supports the fullness of human thriving by re-imagining what that thriving entails and engaging in practices to facilitate it. The Church as teacher can be involved in this education for the purpose of cultural transformation to enhance human flourishing in various arenas. Finally, this dissertation particularly proposes that this education can happen in higher education, in parishes, and in collaboration with the wider community.Thesis (PhD) — Boston College, 2017.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Religious Education and Pastoral Ministry
Identification of an N-hydroxyguanidine reducing activity of xanthine oxidase
A guanoxabenz [1-(2,6-dichlorobenzylideneamino)-3-hydroxyguanidine; an N-hydroxyguanidine] reducing enzymatic activity of rat spleen cytosol was investigated by means of protein purification and N-terminal amino acid sequencing, the reducing activity was shown to reside in xanthine oxidase. The action of the enzyme on guanoxabenz resulted in the formation of guanabenz [1-(2,6-dichlorobenzylideneamino) -3-guanidine]; the product formation could be monitored by HPLC and its identity was confirmed by NMR analysis. The reduction of guanoxabenz required xanthine or NADH as reducing substrates, while the process could be blocked by allopurinol, a selective inhibitor of xanthine oxidase. By using bovine milk xanthine oxidase, the guanoxabenz reducing activity of the enzyme was also verified. We conclude that guanoxabenz is a novel electron acceptor structure for xanthine oxidase.publishersversionPeer reviewe
Light scattering study of the “pseudo-layer” compression elastic constant in a twist-bend nematic liquid crystal
The nematic twist-bend (TB) phase, exhibited by certain achiral thermotropic liquid crystalline (LC) dimers, features a nanometer-scale, heliconical rotation of the average molecular long axis (director) with equally probable left- and right-handed domains. On meso to macroscopic scales, the TB phase may be considered as a stack of equivalent slabs or “pseudo-layers”, each one helical pitch in thickness. The long wavelength fluctuation modes should then be analogous to those of a smectic-A phase, and in particular the hydrodynamic mode combining “layer” compression and bending ought to be characterized by an effective layer compression elastic constant Beff and average director splay constant Keff1. The magnitude of Keff1 is expected to be similar to the splay constant of an ordinary nematic LC, but due to the absence of a true mass density wave, Beff could differ substantially from the typical value of ∼10⁶ Pa in a conventional smectic-A. Here we report the results of a dynamic light scattering study, which confirms the “pseudo-layer” structure of the TB phase with Beff in the range 10³–10⁴ Pa. We show additionally that the temperature dependence of Beff at the TB to nematic transition is accurately described by a coarse-grained free energy density, which is based on a Landau-deGennes expansion in terms of a heli-polar order parameter that characterizes the TB state and is linearly coupled to bend distortion of the director
A quality monitor and monitoring technique employing optically stimulated electron emission
A light source directs ultraviolet light onto a test surface and a detector detects a current of photoelectrons generated by the light. The detector includes a collector which is positively biased with respect to the test surface. Quality is indicated based on the photoelectron current. The collector is then negatively biased to replace charges removed by the measurement of a nonconducting substrate to permit subsequent measurements. Also, the intensity of the ultraviolet light at a particular wavelength is monitored and the voltage of the light source varied to maintain the light a constant desired intensity. The light source is also cooled via a gas circulation system. If the test surface is an insulator, the surface is bombarded with ultraviolet light in the presence of an electron field to remove the majority of negative charges from the surface. The test surface is then exposed to an ion field until it possesses no net charge. The technique described above is then performed to assess quality
A competitive and reversible deactivation approach to catalysis-based quantitative assays
Catalysis-based signal amplification makes optical assays highly sensitive and widely useful in chemical and biochemical research. However, assays must be fine-tuned to avoid signal saturation, substrate depletion and nonlinear performance. Furthermore, once stopped, such assays cannot be restarted, limiting the dynamic range to two orders of magnitude with respect to analyte concentrations. In addition, abundant analytes are difficult to quantify under catalytic conditions due to rapid signal saturation. Herein, we report an approach in which a catalytic reaction competes with a concomitant inactivation of the catalyst or consumption of a reagent required for signal generation. As such, signal generation proceeds for a limited time, then autonomously and reversibly stalls. In two catalysis-based assays, we demonstrate restarting autonomously stalled reactions, enabling accurate measurement over five orders of magnitude, including analyte levels above substrate concentration. This indicates that the dynamic range of catalysis-based assays can be significantly broadened through competitive and reversible deactivation
A case of acute myeloid leukemia with promyelocytic features characterized by expression of a novel RARG-CPSF6 fusion
Key Points
Novel RARG-CPSF6 fusion in an AML case with promyelocytic features and no evidence of PML-RARA or X-RARA fusion. Gene fusions involving RARG can initiate AML with promyelocytic morphological features.</jats:p
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