2,023 research outputs found

    Study of Apollo water impact. Volume 6 - User's manual - Interaction Final report

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    Computer program for hydroelastic responses of flexible shells of revolution during axially symmetric impact into incompressible fluids as in Apollo water impac

    Reconsidering NEPA

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    The National Environmental Policy Act (NEPA) ushered in the modern era of environmental law. Thanks to its environmental impact statement (EIS) provision, it remains, by far, the most litigated environmental statute. Many administrations have sought to weaken the law. The Trump administration, for example, put into place regulations that strictly limit the EIS process, which the Biden administration seems poised to roll back. For the most part, however, NEPA has shown remarkable staying power and resilience since its passage just over fifty years ago. As a result, its legislative history remains relevant. But the accepted history of NEPA is deeply flawed. By bringing the history to light, this Article makes three contributions. First, relying on both original primary sources and a thorough review of the literature, we provide a nuanced and engaging history of the EIS provision, correcting common misconceptions of the accepted story. Second, we show why understanding this more accurate history of the Act’s key provision can rebut major threats to NEPA and the regulations that govern it, such as those introduced during the Trump administration. Third, our granular history of NEPA provides an ideal experiment to test the accuracy of traditional canons of legislative history. We find that most canons fail to recognize the most critical aspects of NEPA’s history. Positive political theory–derived canons, on the other hand, most accurately capture the actual legislative history

    Semitransparent organic photovoltaic cells

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    We demonstrate semitransparent, small molecular weight organic solar cells employing a thin silver/indium tin oxide compound cathode with a maximum transmission of (60±6)%(60±6)% averaged over the visible spectral range and with a power conversion efficiency, ηp = (0.28±0.03)%ηp=(0.28±0.03)% under simulated, AM1.5G, 1 sun illumination. By increasing the Ag thickness, an average transmission of (26±3)%(26±3)% is achieved with ηp = (0.62±0.06)%ηp=(0.62±0.06)%, a value approximately half of that obtained for the same structure employing a conventional, reflective, and thick Ag cathode. A semitransparent tandem organic solar cell with ηp = (0.48±0.02)%ηp=(0.48±0.02)% and an average transmission of (44±4)%(44±4)% is also demonstrated. Semitransparent organic photovoltaic cells have potential uses as tinted and power-generating thin-film coatings on architectural surfaces, such as windows and walls. The use of a transparent top electrode also significantly simplifies the design of tandem cells, relaxing requirements for the placement of different absorbing materials at the maxima of optical fields introduced by reflective cathodes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87783/2/233502_1.pd

    The frictional Schr\"odinger-Newton equation in models of wave function collapse

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    Replacing the Newtonian coupling G by -iG, the Schrodinger-Newton equation becomes ``frictional''. Instead of the reversible Schrodinger-Newton equation, we advocate its frictional version to generate the set of pointer states for macroscopic quantum bodies.Comment: 6pp LaTeX for J.Phys.Conf.Ser.+2 figs. Talk given at the Int. Workshop DICE2006 "Quantum Mechanics between Decoherence and Determinism: new aspects from particle physics to cosmology" Piombino, Sept 11-15, 200

    Comments on Proposed Gravitational Modifications of Schrodinger Dynamics and their Experimental Implications

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    We discuss aspects of gravitational modifications of Schrodinger dynamics proposed by Diosi and Penrose. We consider first the Diosi-Penrose criterion for gravitationally induced state vector reduction, and compute the reduction time expected for a superposition of a uniform density cubical solid in two positions displaced by a small fraction of the cube side. We show that the predicted effect is much smaller than would be observable in the proposed Marshall et al. mirror experiment. We then consider the ``Schrodinger -Newton'' equation for an N-particle system. We show that in the independent particle approximation, it differs from the usual Hartree approximation applied to the Newtonian potential by self-interaction terms, which do not have a consistent Born rule interpretation. This raises doubts about the use of the Schrodinger-Newton equation to calculate gravitational effects on molecular interference experiments. When the effects of Newtonian gravitation on molecular diffraction are calculated using the standard many-body Schrodinger equation, no washing out of the interference pattern is predicted.Comment: Tex, 17

    A Single Antibody based ELISA for the N-terminal sequence of BAG-75, a New Biomarker for Bone Formation [abstract]

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    Biomedical Tissue Engineering, Biomaterials, & Medical Devices Poster SessionBone acidic glycoprotein-75 (BAG-75) is a secreted product of osteoblastic cells localized predominantly to areas of new bone formation. We have identified the N-terminal sequence of BAG-75 as LPVARYQNTEEEE and shown that anti-peptide antibodies against residues #3-13 only recognize the 75 kDa precursor and apparent 50 kDa fragment in serum and in osteoblastic cultures. Formation of the 50 kDa fragment is blocked by AEBSF, a serine protease inhibitor which we also showed blocks mineralization in osteoblastic cultures. Measurement of BAG-75 and its fragment concentration in serum represents a new method to estimate the rate of new bone formation in vivo. Our purpose was to establish an anti-VARYQNTEEEE peptide antibody based ELISA test to measure cross-reactive proteins released from bone into blood. Western blotting was performed using young rat serum from different ages, rats subjected to ovariectomy (OVX) or sham surgery, and normal human serum. Immunoreactive 50 kDa fragment peaked at 18 days after birth which parallels bone formation. Ovariectomized rats displayed a peak of 50 kDa immunoreactivty at 21 days after surgery which corresponds to a spike in bone formation in this model (~2.5-fold above controls). Comparable assays for osteocalcin showed only a 39% increase. Also, human serum contains a 50 kDa protein which cross-reacts with anti-VARYQNTEEEE antibodies. We then established a competitive 96-well ELISA using anti-peptide antibody and new sera at 21 days from ovariectomized or sham rats, a model for stimulated bone formation. VARYQNTEEEE peptide conjugated to keyhole limpet hemocyanin (KLH) was used as the bound antigen. KLH-peptide amount, primary antibody concentration, secondary antibody concentration, and blocking agent were optimized in a series of experiments. Optimal conditions were determined to be 2 µg input KLH-peptide per well, 1/5,000 dilution of primary anti-VARYQNTEEEE antibody, 1/10,000 dilution of secondary antibody, and gelatin as a blocking agent. Sera from OVX rats and sham-operated controls were compared to the standard curve (r = 0.9923) created with free KLH-peptide as competitor to determine the equivalent amount of KLH-peptide present. OVX sera (n=3) contained an average 2.6 x 10-4 (+/- 1.4 x 10-4) µg peptide equivalent versus 1.05 x 10-4 (+/- 0.68 x 10-4) µg for sham sera (n=3). The difference was not significant (t-test, p=0.157), however, doubling the sample size is predicted to yield significance. Conclusions: A. Cross-reactive 75 kDa and 50 kDa proteins are present in human and rat serum and increase in concentration when bone formation is stimulated. B. A new, single antibody based ELISA assay was established to quantitate antigen released from bone into blood. C. In contrast to other commercial bone formation assays (collagen peptides and osteocalcin), the size of cross-reactive protein (>50 kDa) should preclude kidney filtration and facilitate measurement. D. This serum biomarker undergoes a 2-3 fold average increase within 3 weeks after simulation of bone. This test may be useful to monitor the early response to stimulatory therapy in osteoporosis patients or to repressive glucocorticoid therapy in sarcoidosis patients. Currently, a 1% change in bone mineral density requires 12-18 months to detect by x-ray methods
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